Boston Marathon bombs said to be made from pressure cookers

The FBI said Tuesday it is co-ordinating a "worldwide investigation" into the twin bomb blasts that killed three people and wounded more than 170 others near the Boston Marathon finish line.

"We will go to where the evidence and the leads take us," FBI special agent Rick DesLauriers said at a media briefing a day after the explosions.
Timeline of Boston Marathon bombing
"We will go to the ends of the Earth to identify the subject or subjects who are responsible for this despicable crime, and we will do everything we can to bring them to justice," he said.
Both Boston police Commissioner Edward Davis and Gov. Deval Patrick clarified earlier reports that said up to seven unexploded bombs may have been found in the city, confirming that only two bombs were involved in the attack.
DesLauriers would not comment on the "nature of the devices" that exploded within 10 seconds of each other on Boylston Street in Copley Square.
However, The Associated Press reported that a person briefed on the investigation, who was not identified, said the bombs were fashioned out of pressure cookers and packed with shards of metal, nails and ball bearings.

The near-simultaneous explosions occurred near the finish line — about 100 metres apart.
Davis on Tuesday said there were 176 casualties in total. Seventeen of them were in critical condition, and three died.
Boston Globe photographer John Tlumacki said the bombs went off 1½ hours after the first runners crossed the finish line.
"The initial blast jolted me and dropped a runner onto the ground." That man, who suffered minor injuries, has been identified as 78-year-old Bill Iffrig of Washington state, who was running his third Boston Marathon.
Police don't know who launched the attack or why, U.S. President Barack Obama said on Tuesday.
"This was a heinous and cowardly act, and given what we now know about what took place, the FBI is investigating it as an act of terrorism. Any time bombs are used to target innocent civilians it is an act of terror," Obama said.
"We will pursue every effort to get to the bottom of what happened," he added.
State police said officers with a search warrant related to the investigation searched a fifth-floor apartment unit Monday night in the Boston suburb of Revere, but provided no further details. Investigators were seen leaving the building early Tuesday carrying brown paper bags, plastic trash bags and a duffel bag.
The Pakistani Taliban have threatened to attack the U.S. in the past, but the group’s spokesman Ahsanullah Ahsan denied involvement in a telephone call with The Associated Press.
The Boston Marathon is held on Patriots Day, a civic holiday that commemorates one of the first battles of the American Revolution.
One of those killed was an eight-year-old boy identified in local media reports as Martin Richard of Boston's Dorchester neighbourhood. He was watching his father race. There were reports mother and sister were critically injured.
Bombing victim, 8, was waiting for father
Eight hospitals said they were involved in treating people. The injuries ranged from cuts and bruises to amputations. Many victims suffered lower-leg injuries and shrapnel wounds. Some suffered ruptured eardrums.
Among the badly injured spectators are two brothers, ages 31 and 33, from the Boston area, who each lost a leg from the knee down.
Dr. Natalie Stavas, a pediatric doctor in Boston who was running in the marathon, was one of many people who raced to the scene to help treat the injured.
"I was a critical care nurse for quite some time and have worked in trauma emergency rooms, and none of that prepared me for the devastation and the horror that was at the finish line," she said.
Dr. George Velmahos, chief of trauma at Massachusetts General Hospital, said doctors at the facility have performed four amputations. He said many of the wounds were caused by "small metallic fragments" such as pellets and nails.
Boston Globe video of marathon explosion
CNN reported amputations have been carried out on 10 patients in total.
Investigators are examining the remains of the explosive devices, described as relatively small and crude.
The blasts shattered windows and sent dense plumes of smoke rising over the street. Emergency workers and national guardsmen on crowd control duty began climbing over and tearing down temporary fences to get to the blast site.
Competitors and race organizers were crying as they fled the chaos. Bloody spectators were carried to the medical tent that had been set up to care for fatigued runners.
Roupen Bastajian, a 35-year-old state trooper from Smithfield, R.I., had just finished the race when they put the heat blanket wrap on him and he heard the blasts.
"I started running toward the blast. And there were people all over the floor," he told The Associated Press. "We started grabbing tourniquets and started tying legs. At least 25 to 30 people have at least one leg missing, or an ankle missing, or two legs missing."
"They just started bringing people in with no limbs," runner Tim Davey, of Richmond, Va., told the Associated Press. He said he and his wife, Lisa, tried to keep their children's eyes shielded from the gruesome scene inside a medical tent that had been set up to care for fatigued runners, but "they saw a lot."
Mike Murphy, a former New Brunswick health minister, was there with his wife Moira at the finish line of the marathon, waiting for their son Timothy to finish. He told CBC News that after the explosions his wife helped a woman in front of her whose running gear was "melting into her skin."
Foreign Affairs officials told CBC News that there were no reports of any Canadians injured in the blasts.
According to the Boston Marathon website, 2,078 Canadians were listed as entrants among the 23,000 people in the race.
"We have had, of course, as you would expect, close consultation with security officials in the United States," Canada's Defence Minister Peter MacKay said on Tuesday.
"I won't speak to any specific change in the security atmosphere here, but certainly we are always vigilant in the aftermath of an incident such as this."
Michael Doyle, a Canadian who was in the marathon, said he heard sirens and "quite a bit of commotion" on Monday afternoon. "Then I heard there were two explosions, one of them close to the finish line, another further up."
Canadians describe blast 'fear' and 'shock'
"It's [a] very surreal situation," the web producer for Canadian Running magazine told CBC News.
"As I was making my way closer to the scene here, it was a mixture of people who were very upset and crying, and who seemed to be cognizant of what was going on, and those who I think were completely unaware of the situation," he said.
Runner Laura McLean of Toronto said she heard two explosions outside the medical tent.
"There are people who are really, really bloody," McLean said. "They were pulling them into the medical tent."
Calgary’s Kirsten-Ellen Fleming had been watching the race near the finish line and then headed into a restaurant on the corner of Boylston and Newbury streets.
“We were coming out of the restaurant and there were two big explosions and a bunch of smoke.… It was just immediate chaos and mayhem and confusion,” she said.
"Everyone was just in utter shock and looking around."
Some runners were still going and confused, she said. “Within a very short amount of time, minutes, there were just sirens everywhere. It just sounded like an absolute war zone. People were crying, on the pavement, like sitting down with their head between their knees. Everyone was on their phone, obviously calling loved ones to let them know they were OK."
Marathon runner Lisa Bentley described the initial explosion to CBC News, saying she "heard this big explosion, and then felt the ground shake."
Bentley, who believes she was between 100 and 200 metres from the finish line, said that "very soon after" she felt another big bang, followed by more shaking.
"We didn't know what had happened at all — we just started seeing the lights and the sirens and the emergency vehicles and we thought we've just got to get away from here, so we kept walking away from the finish line," said Bentley, who had already finished the race at the time of the explosion.
Boston's police commissioner told reporters on Tuesday the area around the crime scene has been reduced from 15 blocks to 12, but that it may take two more days to collect all the evidence there before it’s completely re-opened to the public.
"There has to be hundreds if not thousands of photos or videos or observations that were down at that finish line yesterday," said Timothy Alben, superintendent of the Massachusetts State Police at Tuesday's briefing in Boston.
Meanwhile, security precautions are in place at the Canadian consulate in Boston, but the building is open.