One suspect in the Boston Marathon bombings is dead and police were engaged in a massive manhunt Friday morning for a second man following a bloody overnight shootout that left a police officer dead.

The city of Watertown, Mass. was effectively on lockdown and police were urging residents to stay in other communities � including Cambridge, Belmont, Newton and parts of Boston � to remain in their homes.

According to the Associated Press, the suspects may have thrown explosives from the stolen vehicle before one of them was gravely injured. The man, identified publicly in photos earlier Thursday wearing a black baseball cap, died later of multiple gunshot wounds, the AP said.

"We believe this to be a terrorist. We believe this to be a man who's come here to kill people. We need to get him in custody," Boston Police Commissioner Ed David told reporters.

At a media briefing Friday morning, police said they had shut down Boston's public transit system and were preventing cars from entering or leaving Watertown. Several local universities were closed and police told business owners not to open on Friday. Thousands of police officers were fanning out block by block through Newtown. Authorities urged residents only to open their doors to police.

�We are asking you to stay indoor to stay indoors for the time being," said one police officer. "This situation is grave.�

http://thehill.com/video/in-the-news/294...rathon-bombings