'Obama vows to hold culprits of Boston blasts accountable

'These runners just finished and now they don't have legs': Witnesses recount war zone at Boston Marathon as bombs left 26th mile littered with disembodied limbs and 'shoes with flesh still in them'

At least two people have died and dozens are believed to have been wounded when two huge explosions detonated near the finishing line of the Boston Marathon.

Boston police said two had died in the bomb blasts and up to 64 people had been wounded. Witnesses said that some of the injured had lost limbs.

Pools of blood stained the pavements as the two blasts ripped through the area within about 30 seconds from each other near the city’s central Copley Square as people gathered to watch one of the world’s biggest marathons.  Some witnesses said that the first explosion seemed to have come from a building while they weren't sure about the second one. See more pics below....