Russian investigators say have found metro bomb suspect's body parts

Russia's state investigative committee said on Tuesday that the deadly St Petersburg metro blast was caused by a bomb that had possibly been detonated by a man whose body parts were found in one of the train carriages.

"It has been ascertained that an explosive device could have been detonated by a man, fragments of whose body were found in the third carriage of the train," the committee, which has sweeping powers, said in a statement.

"The man has been identified but his identity will not be disclosed for now in the interests of the investigation," the statement added.