One of the suspects in the Boston Marathon bombing has been arrested, according to the Boston Globe, which has quoted "an official with knowledge of the investigation".
Gunfire and explosions have erupted in streets close to Boston's prestigious Massachusetts Institute of Technology after a police officer was shot dead this evening.
The Globe said one suspect in Monday's Boston Marathon bombings has been captured, but another remains on the loose in Watertown after a firefight with police.
Local television station WHDH said one of the suspects has died.
The Boston police scanner told officers they were searching for a white male, with a gray hoodie and dark curly hair, armed with an assault rifle and possible explosives. 波士顿警方是通过警用扫描仪确认，他们在找的嫌犯是个白人男子，留着黑色卷发穿着灰色的帽衫，随身携带冲锋步枪，并可能还携有爆炸物。
He is believed to the suspect wearing a white hat, seen in surveillance footage released today.