The FBI has released pictures and video of two suspects in the Boston Marathon bombing.
The agency said it was seeking the public's help in finding the two men, who are seen on the crowded street before Monday's bombs exploded near the race's finish line.
Richard DesLauriers, the US Federal Bureau of Investigation's special agent in charge in Boston, said the men were "armed and extremely dangerous" and carried backpacks that are believed to have contained the bombs.
"Today we are enlisting the public's help to identify the two suspects," he said at a news conference.
Was wearing a black hat and backpack.
Suspect 2 was wearing a white hat and a backpack and was seen walking behind Suspect 1.
The FBI also released surveillance video showing the two suspects walking one behind the other.