'Pulling nails out of a little girl's flesh is just awful': Surgeons reveal horror of Boston bombings

Bystanders tend to people injured by the explosions at the finishing line of the Boston Marathon on Monday (EPA)

Surgeons have spoken of their horror as they were forced to amputate several limbs following many “lower extremity” wounds caused by flying shrapnel from the Boston bombs.

After law enforcement officials said a pressure cooker stuffed with gunpowder and shrapnel caused at least one of the blasts, medics spoke of their decision to amputate limbs that were “beyond salvation” among the 176 wounded.

At least 10 people who had limbs amputated after the blast with the floor-level explosion causing injuries below the waist, including bone, soft tissue and vascular damage.

Doctors said the amputations had been part of a frantic bid to stop patients bleeding to death.

“When these kids came in... they were just so badly hurt, just covered with singed hair and in so much pain, it was just gut-wrenching,” said David Mooney, the director of the trauma program at the Boston Children's Hospital.

He added: “Pulling nails out of a little girl's flesh is just awful.”

George Velmahos, chief of trauma surgery at Massachusetts General Hospital, told reporters that he had been forced to complete the “ugly job that the bomb did”.

The hospital had amputated four limbs, Dr Velmahos said, while two other patients remain “at risk”.

He said: “Some of them woke up today with no leg and they told me that they are happy to be alive. They told me they thought they would die as they saw the blood spilling out.”

The FBI has confirmed that pressure cookers may have been used in the bombings with pieces of black nylon and fragments of ball bearings and nails discovered at the scene.

FBI special agent Richard DesLauriers said it was believed that the bombs were placed in a dark-coloured backpag or bag.

Dr Velmahos said that in his professional opinion the shrapnel had originated from the bombs. He said: “My opinion is that most of them were in the bomb.”

He added that pea-sized pellets and headless nails had been recovered from victims with some people hit by up to 30 pieces of flying shrapnel.

“I think it’s unlikely they would be so consistent if they were pulled out from the environment,” Dr Velmahos told reporters outside the hospital.

Dr Ron Walls, an emergency doctor from Brigham and Woman’s Hospital in Boston added that the items were “clearly designed to be projectiles that were built into the device”.