Boston/Washington, April 16 (IANS): Three people, including an eight-year-old boy, were killed and 144 injured as terror returned to the US with two powerful explosions striking the world's oldest annual marathon in the city of Boston. President Barack Obama vowed that those responsible would feel the "full weight of justice".
The two successive blasts rocked the Boston Marathon finish line Monday afternoon.
And when the smoke cleared after the blasts in Boston's Back Bay section, dozens of victims lay in the street, some unconscious, some grievously injured, including some whose limbs had been torn off by the blast, Boston Globe reported.
The dead in the US' worst terror attack since 9/11 included an eight-year-old boy. Hospitals reported 144 people were being treated. Amongst them was a nine-year-old girl, a seven-year-old boy, a 12-year-old and a two-year-old at the Boston Children's Hospital.
Shaken witnesses described scenes of chaos and horrific injuries.
"It was just immediately (evident) there were injuries, right in the middle of the spectator crowds," said boston.com sports producer Steve Silva, who was on the scene to cover the race.
"There was blood everywhere; there were victims being carried out on stretchers. I saw someone lose their leg. People are crying. People are confused," Silva, who shot shocking video of the explosions was quoted as saying.
Oscar Otero was barely a few feet away.
"There was blood all over the place. I saw a leg, people with bones sticking out of their skin," he said.
"It's hard to describe."
John Ross, a spectator, said: "Somebody's leg flew by my head."
"I gave my belt to stop the blood," bostonherald.com quoted him as saying.
The 2013 Boston Marathon is the 117th edition of the event, which was first held in 1897. It is the world's oldest annual marathon and one of six World Marathon Majors.
The race, which runs through 42.195 km, is always held on Patriot Day, the third Monday of April. It attracts about 20,000 athletes around the world each year, one of the world's largest marathons.
Chaos erupted as near-simultaneous blasts struck about 90 metres apart, the first on Boylston Street near the photo bridge that marks the finish line, CTV News said.
Police warned to be on the lookout for a "darker-skinned or black male" with a possible foreign accent in connection with the attack, reports said, citing a law enforcement advisory obtained by it.
The man was seen with a black backpack and sweatshirt and was trying to get into a restricted area about five minutes before the first explosion.
Also, a Saudi national with a leg wound was under guard at a Boston hospital in connection with the bombings, but investigators could not say whether he was at this time.
Authorities in Boston found at least one other explosive device that they were dismantling, an official said.
Both bombs were said to be small, and initial tests showed no C-4 or other high-grade explosive material, suggesting that the packages used in the attack were crude explosive devices.
President Obama pledged that those responsible would feel the "full weight of justice".
"The American people will say a prayer for Boston tonight," he said. The president cautioned that authorities were still investigating and that people should not jump to any conclusions.
"But make no mistake," Obama said. "We will get to the bottom of this and we will find out who did this. We'll find out why they did this and we will hold them accountable."
In New Delhi, Prime Minister Manmohan Singh joined world leaders in condemning the terror attack in Boston. In a letter to Obama Tuesday, he described it as a "senseless and cowardly act of violence" and offered India's full support in combating terror.
"In keeping with the excellent cooperation between India and the United States to combat terrorism, we offer you our full support," the prime minister wrote.