US President Barack Obama has been briefed on the unfolding situation in Boston overnight, according to the Associated Press.
Among those terribly injured by the Boston marathon bombs was a dance instructor. Adrianne Haslet-Davis lost her foot in the explosion.
The mother of the two brothers suspected of carrying out the Boston bombings told ITV News they saw last year's race but are innocent.
Boston's marathon bombing suspect Dzohkhar Tsarnaev was charged with an offence that could lead to the death penalty, if he is found guilty.