Detectives investigating the Boston Marathon bombing are pursuing three major lines of inquiry after the worst terrorist attack on US soil since 9/11.
A wide-scale manhunt is underway for a mysterious, hooded ‘man in black’, seen loitering suspiciously near the finish line with a backpack moments before the blasts went off.
Meanwhile, agents, including the FBI and bomb disposal officers, swooped on an apartment in the suburbs of the city after questioning another man spotted driving erratically around state police barracks.
And a third man of Saudi origin is under police guard in hospital, where he is being treated for burns to his legs, after he was tackled to the ground by a civilian who believed he too was acting suspiciously.
A European security official said Tuesday initial evidence indicates that the attacks were not the work of suicide bombers.
“So far, investigators believe it was not the work of suicide bombers, but it is still too early to rule it out completely,” said the official, who spoke from the United States on condition of anonymity because he was not authorized to speak about the U.S. investigation.
The Pakistani Taliban, which has threatened attacks in the United States because of its support for the Pakistani government, on Tuesday denied any role in the marathon bombings.