Pressure cookers may have been used in marathon attack. Fox News
THE FBI has confirmed the Boston Marathon bombs may have been made from pressure cookers after recovering fragments of dark nylon, BBs and nails from the scene.
FBI special agent-in-charge Rick Deslauriers told a media conference that both explosives were placed inside black nylon bags or backpacks.
LIVE UPDATE. ALL TIMES ARE AEST
5.48pm: More than 2000 tips have been received following a public appeal by the FBI to help solve the Boston Marathon bombings.
5.30pm: The Tribeca Film Festival was born out of the 9/11 terror attacks and celebrities attending an annual Vanity Fair gala in New York City to kick off this year's event were mindful of the shadow cast by the explosions at the Boston Marathon.
Two men in hazardous materials suits put numbers on the shattered glass and debris as they investigate the scene at the first bombing.
Police and security guards were visible at the festival on Tuesday night, where there was an outdoor metal detector for arriving guests.
Whoopi Goldberg said she understood if some people were apprehensive about going out in crowded, public areas.
''I say that's alright. We're out for you,'' she said.
''Stay until you feel better. But we're out here and we got your back.''
Fox News has released an image of what appears to be an exploded backpack at the scene of the Boston bombings.
Aida Turturro, best known for her role on TV's The Sopranos, said it's important to live your life and not be scared.
''You never know. I mean you can die by crossing the street or you can get hit by a car. . . . I think the best thing is to continue life because if you don't they're winning,'' she said.
''If they keep you from living your life then they've won. They've taken your life away from you right there.''
5.15pm: A Chinese newspaper has named a person they say is the third victim of the Boston Marathon bombings.
Images from the Department of Homeland Security show improvised explosive devices using pressure cookers.
The person has been identified as a Boston University graduate student.
Officials refused to name the third victim at the request of the family.
It was earlier reported that a Chinese student named Lingzi Lu was missing following the Boston Marathon bombings.
Earlier another Chinese student was incorrrectly identified by the Huffington Post as dying. The website later apologised.
Hundreds of mourners gather at Boston Common for a candelight vigil.
4.40pm: The Boston Marathon blasts are typical of the ''lone wolf'', a source with knowledge of the investigations has told CNN.
The source was referring to a lone terrorist who builds a bomb on their own by following a widely available formula.
In this case, the formula has been likened to one that al-Qaeda has recommended to its supporters around the world.
The threat of the "lone wolf" alarms the intelligence community.
The two bombs that exploded at the Boston Marathon have raised fresh alarms about terrorism in the US.
"This is what you worry about the most," the source told CNN.
4.15pm: Spam emails have been reported to the ACMA containing links to webpages associated with the recent Boston explosions.
These emails contain links to potentially malicious content that may damage your computer.
If you get one of these emails the ACMA advises that you should delete it immediately.
3.42pm: With no claim of responsibility for the marathon attack and police not committing to blaming foreign or domestic militants, Boston harbors widespread questions about the perpetrators as the city and the nation paid tribute to the dead, AFP reports.
US authorities have thrown virtually every investigation agency into the hunt with more than 1,000 officers working in Boston alone, said Rick DesLauriers, head of the FBI's Boston office.
"This will be a worldwide investigation," DesLauriers told reporters. "We will go to the ends of the Earth to identify the subject or subjects responsible for this despicable crime," he added.
These images show the devastation caused by the bombing - and the massive emergency services operation as authorities scrambled to help the injured and search for more devices.
3.20pm: Broadcaster Alan Jones' claim that the tragic bombings were the work of left-wing radical students in Boston and that Australia should seriously look at its intake of overseas students as result, is totally inaccurate according to our own Ian McPhedran.
His disturbing conspiracy theory shows just how ignorant he is about terrorism and hate crimes, as our defence correspondent points out.
3.05pm: While all eyes are on the tragic events in Boston, a US drone has fired two missiles on a Taliban base in Pakistan, killing five militants.
The Taliban and al-Qaeda have denied links to yesterday's bombings, but the US campaign against terrorists continues.
People in hazardous materials suits investigate the scene at the first bombing on Boylston Street in Boston.
Authorities investigating the double bombing in Boston are keen to also point out that the Saudi student who is in hospital with burns, is a witness not a suspect, according to The Washington Post.
3.00pm: China's Internet users on Wednesday mourned a Chinese national killed in the Boston marathon bombing as others attacked the exposure of the victim's name despite a family request for anonymity, AFP reports.
Thousands posted messages online after the consulate in New York said a Chinese citizen was among three people killed in the explosions in the US city yesterday.
"Terrorism has no national limits, the victims have no national limits. Together we condemn, together we mourn," one user of Sina Weibo, a social networking site similar to Twitter, wrote.
U.S. President Barack Obama says the FBI is investigating the Boston bombings as an "act of terror" -- the day after the attack killed 3 people and sent 176 to area hospitals. Rough Cut (no reporter narration).
"Poor child, go peacefully," wrote another.
2.40pm: MUSLIMS in the US are watching closely as the investigation into the Boston bombings unfolds, fearing a backlash like after 9/11 if an Islamist link is confirmed to the deadly attack, AFP reports.
Several Muslim groups issued statements within hours of the double bombing, strenuously condemning the attacks which killed three and injured more than 100 people.
A spokesman for the Council on American-Islamic Relations (CAIR), Ibrahim Hooper, said the Muslim group had already received "the usual hate calls," but nothing major as yet - and underlined its main message was condemnation.
Amateur video shot from a reviewing stand shows the aftermath of two explosions near the finish line of the Boston Marathon. Rough Cut (no reporter narration).
"You don't want to create the impression that you're more concerned about vandalism at a mosque, or something like that, than you are about a violent attack that takes the lives of individuals and injures many more," he said.
But he also said: "In any of these cases that's something that's in the back of our mind, that there's a possibility of a backlash. We'll just have to see how the investigation develops."
The number of FBI-designated hate crimes against Muslims and Arabs in America shot up dramatically after the September 11, 2001 attacks, which were quickly attributed to Al-Qaeda and a team of mostly Saudi hijackers.
2.10pm: While Bostonians continue to mourn and police search for more clues into who was behind the bombings, here is a visual look at some of the more poignant details emerging from this tragedy.
Humvees and debris could be seen in downtown Boston, the morning after the worst bombing attack on U.S. soil since the September 11th attacks. Rough Cut (no reporter narration).
1.50pm: Hundreds of residents in the tight-knit suburb of Dorchester - the area where eight-year-old victim Martin Richard lived - have gathered at a local park, reflecting on the randomness of the deaths and injuries.
At hospitals throughout the day, families of survivors and physicians recounted the scenes that continued to haunt them. Surgeons told of wheeling badly injured patients directly into the operating room after they had lost so much blood that their organs were in danger of failing and amputating what was left of their legs on the spot.
"We just finished the job that the bomb did - their limbs were completely mangled, some hanging by a shred,'' said George Velmahos, chief trauma surgeon at Massachusetts General Hospital.
1.30pm: The official Chinese news agency Xinhua says relatives have requested that the third victim of the Boston bombings, a Boston University graduate student, not be identified.
London's Telegraph reports that Phoenix Satellite Television Holdings, a Hong Kong-based broadcaster with ties to the Chinese government, said the woman from the northeastern Chinese city of Shenyang .
1.10pm: In another tragic twist, the family of Jeff Bauman, the young man who lost his legs in the bombings, learned of his fate from an image of their son being tended to by Carlos Arredondo, the heroic man in the cowboy hat, the New York Times says.
When the bombs went off, Jeff Bauman called his son's mobile repeatedly - but got no answer. His son was there to cheer on his girlfriend, Erin Hurley, who was running her first Boston Marathon.
He learned of his son's fate after his stepdaughter called, asking him if he'd seen "the picture", which he then found on Facebook. By the time he got to the hospital, the surgery had been done - both Jeff's legs had been amputated at the knee.
12.58pm: Britain's Prince Harry will honour a commitment to appear at the London Marathon this weekend, despite security concerns following the horrific bombings at the Boston Marathon.
12.46pm: Emergency officials are doing a sweep of the Hollywood lot, where KTLA TV is based, which also includes other syndicated shows.
12.42pm: The New York Yankees paid tribute to victims of the Boston Marathon bombings by playing the Fenway Park favorite Sweet Caroline at Yankee Stadium. The popular sing-along song has been featured at Boston Red Sox home games since 2002.
"Thank you NY Yankees for playing 'Sweet Caroline' for the people of Boston," singer Neil Diamond wrote on his Twitter page. "You scored a home run in my heart. With respect, Neil #OneBoston."
12.30pm: KTLA TV in Los Angeles is being evacuated after a threat was called in to the station.
11.29am: Boston Marathon organisers say next year's race will go ahead as planned and that they are co-operating with law enforcement officials to find those responsible for the deadly blasts.
"We are committed to continuing that tradition with the running of the 118th Boston Marathon in 2014," said Thomas Grilk, executive director of the Boston Athletic Association.
"We are co-operating with the city of Boston, the Commonwealth of Massachusetts, and all federal law enforcement officials in the investigation and the effort to bring those responsible for this tragedy to justice, so we are limited in what information we can provide.
"Boston is strong. Boston is resilient. Boston is our home. And Boston has made us enormously proud in the past 24 hours. The Boston Marathon is a deeply held tradition, an integral part of the fabric and history of our community."
11.20am: US President Barack Obama will visit Boston on Thursday. Massachusetts Governor Deval Patrick says Obama will be attending an interfaith service at the Cathedral of the Holy Cross to "help us all heal".
11am: The Boston Red Sox hope their return to the field will help their wounded city heal. The clubhouse mood was sombre as the team prepared for a three-game series with the Indians.
Boston outfielder Jonny Gomes says the players have "heavy hearts" as they get ready to play while their city recovers. Pitcher Jon Lester says the tragedy "really hits home. Boston's my home, just like everybody in this clubhouse."
The Red Sox and Indians will wear black armbands to honour the victims. A moment of silence will be observed before the first pitch.
10.48am: The bombs that tore through a crowd of spectators at the Boston Marathon could have cost as little as $100 to build and were made of the most ordinary ingredients - so ordinary, in fact, that investigators could face a gargantuan challenge in attempting to use bomb forensics to find the culprit, the Washington Post says.
The bomb's simplicity complicates the task of determining whether the maker was an international terrorist, a homegrown extremist or a local citizen with a grudge, investigators and experts say.
10.17am: A partial circuit board recovered by the FBI from the Boston bomb site has been sent to Quantico for analysis.
10.06am: A US food website has been forced to apologise after using the Boston bombings to try to spruik its scones.
New York-based Epicurious tweeted: "In honour of Boston and New England, may we suggest: whole-grain cranberry scones!"
Social media users were quick to criticise, accusing Epicurious of badly misjudging the public mood.
9.52am: A Chinese student is the third person killed in the Boston Marathon blasts, the Chinese Consulate in New York says.
An official at the consulate's press section, said that one student was injured and another died in the blasts.
Boston University said on its website that the victim, a graduate, was among a trio of students who had gone to watch the race at the finish line.
9.45am: At least 13 of the 183 people injured in Boston terror attack have had amputations, CNN reports.
9.30am: In a tragic hospital mix-up, the family of Boston bombing victim Krystle Campbell were told their daughter had survived and was being operated on in hospital - only to find out later she was dead.
The 29-year-old's parents were first told by doctors that she had survived, but that her friend, Karen Rand, had died.
When William and Patty Campbell were finally allowed in to see the patient, they realised it was not their daughter, Boston news channel WCBV reported.
9.21am: Reports of a suspicious package have closed College Road on Ohio State University's campus.
9.20am: Egypt's Muslim Brotherhood has condemned the Boston bombings, calling the blasts "criminal".
9.10am: Hundreds have gathered on Boston Common to honour the victims of the bombings.
9am: Fox News has obtained exclusive photographs of bomb fragments from the crime scene of the Boston blasts.
Fox News has released images it claims are bomb fragments from the scene of the Boston Marathon blasts. Source: Supplied
8.50am: Senate Majority Leader Harry Reid has confirmed the ricin attack, saying the letter was addressed to Senator Wicker, a Republican from the state of Mississippi.
The letter was tested at the Senate building's mail office where preliminary tests found it to contain poison. Ricin is a toxic protein that can kill an adult who inhales even a small amount.
8.28am: Fox is pulling from websites a recent episode of Family Guy that depicts mass deaths at the Boston Marathon and has no immediate plans to air it again. Fox spokeswoman Gaude Paez says the episode has been removed from Fox.com and Hulu.com.
8.15am: In breaking news, an envelope sent to the office of Senator Roger Wicker has tested positive for the deadly poison ricin at the US Capitol's off-site mail facility in Washington DC.
8.10am: Boston University says a graduate student at the school was the third victim killed in the Boston Marathon bombing.
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Earlier, it was reported how similar pressure-cooker explosives have been used in Afghanistan, India, Nepal and Pakistan, according to a July 2010 intelligence report by the FBI and Homeland Security.
Deslauriers said the forensic evidence recovery was being carried out "methodically, carefully, yet with a sense of urgency".
The bombs killed three people and injured at least 176 when they were detonated near the finish line of the Boston Marathon.
DesLauriers said yesterday's focus of rescue and saving lives was now fully focused on finding the Boston Marathon bombers.
It is not yet clear what kind of explosive was used, he said.
Pressure-cooker bombs are a preferred weapon of al-Qaeda and listed as the "most effective" weapon of jihad, according to an English-language terror magazine called Inspire, in an article entitled 'How to Build a Bomb in the Kitchen of Your Mom', the Mail Online reports.
Investigators in the Boston Marathon probe have also found pieces of an electronic circuit board, which could indicate a timer was used in the detonation.
Also, one of the three devices used in the May 2010 Times Square attempted bombing was a pressure cooker, the report said.
"Placed carefully, such devices provide little or no indication of an impending attack," the report said.
Investigators also found pieces of an electronic circuit board possibly indicating a timer was used in the detonation of the bomb.
Another article in Inspire detailed "the most important enemy targets" for jihadists in America, CNS NEWS reported.
The aim should be to target "human crowds in order to inflict maximum human losses," a terrorist known as Abu Musab al-Suri wrote.
"This is very easy since there are numerous such targets such as crowded sports arenas, annual social events, large international exhibitions etc."
Details of the explosive devices came as authorities identified a second victim killed in the blasts as as 29-year-old Krystle Campbell, from Arlington, Massachusetts.
Eight-year-old Martin Richard, who was waiting at the finish line with his father, mother and brother and little sister, was among those killed when the bombs detonated at the sports event. His mother has undergone brain surgery and his six-year-old sister lost a leg.
FBI agents are leading a massive manhunt for those responsible for the twin blasts.
Investigators do not know of a motive for the bombings, nor do they have a specific suspect or anyone in custody.
Amid the chaos yesterday, it was reported that officials had arrested a Saudi national, who is being treated for burns and shrapnel wounds, in connection to the bombings after a civilian saw him acting suspiciously at the scene.
But now officials have confirmed the man, Abdulrahman Ali Alharbi, 22, is being regarded as a witness, rather than a suspect, the Washington Post reported.
It comes after 20 police and federal officials raided his home in the Boston suburb of Revere on Monday night, but the search turned up nothing.
A doctor treating the wounded said one of the victims was maimed by what looked like ball bearings or BBs.
Federal investigators said no one had claimed responsibility for the bombings, which took place on one of the city's biggest civic holidays, Patriots Day.
President Obama said the bombings were an act of terrorism, but investigators do not know if they were carried out by an international organisation, domestic group or a "malevolent individual". He said, "the American people refuse to be terrorised".
US Defence Secretary Chuck Hagel called the bombings "a cruel act of terror" and said "a thorough investigation will have to determine whether it was planned or carried out by a terror group, foreign or domestic".
Across the US, from Washington to Los Angeles, police tightened security, monitoring landmarks, government buildings, transit hubs and sporting events.
