Residents of Boston were put on high alert overnight as police search for the second of two suspects believed to be responsible for the bombing at the Boston Marathon on Monday.
One of the two suspects was shot dead early Friday.
Local, state and federal law enforcement officers have fanned out in the Boston suburb of Watertown to track him down, Transit Police Spokesperson Paul MacMillan told CNN earlier.
Residents in Watertown, Newton, Waltham, Belmont, Cambridge and the Allston-Brighton neighborhood of Boston were also told to stay indoors
He is believed to be armed and dangerous. Police warned residents to lock their homes and stay away from their windows and doors.