The city and parts of its suburbs have been locked down Friday as the manhunt intensified for the surviving suspect in the Boston Marathon bombing, hours after the other suspect was killed in a dramatic firefight with police in nearby Watertown, authorities said.
A law enforcement official told CBS News the two suspected bombers have been preliminarily identified. They are believed to be from Chechnya or Turkey. They have been in the United States a little over a year. The two men are not students. They are legal permanent residents of the U.S.
The sources say the two are brothers, 19 and 20. One has been identified as Dzhokhar A. Tsarnaev, 19, of Cambridge, Mass.
The fugitive is Dzhokar Tsarnaev, 19, the brother of the dead suspect who was not immediately identified, law enforcement authorities told USA TODAY. Both suspects have been in the U.S. for about a year, living as legal U.S. residents in Cambridge.
The surviving suspect is believed to be the same suspect who dropped a backpack laden with explosives at the site of the second explosion.
Massachusetts Gov. Deval Patrick ordered the entire city of Boston and its surrounding suburbs locked down and its residents to remain in their homes.
Massachusetts shut down all mass transit, including buses and trains, in Boston and surrounding suburbs, Kurt Schwartz, director of Massachusetts Emergency Management Agency said. Schools were closed and classes canceled at most universities.
Boston Police Commissioner Edward Davis says the suspect at large is the one seen in the white hat in images of the Boston Marathon suspects released by the FBI Thursday. Davis says he is “armed and dangerous.”
The Middlesex district attorney said the two men are suspected of killing a Massachusetts Institute of Technology police officer on campus late Thursday, then stealing a car at gunpoint and later releasing its driver unharmed. Hours earlier, police had released photos of the marathon bombing suspects and asked for the public’s help finding them.
Authorities say the suspects threw explosives from the car as police followed it into Watertown. The suspects and police exchanged gunfire, and one of the suspects was critically injured and later died while the other escaped.
Residents of Watertown, a Boston suburb, have been advised to keep their doors locked and not let anyone in. The Boston Police Department warned residents to “stay home,” and barred any vehicles from entering or leaving Watertown.
Public transit in the area has been suspended as authorities searched for the remaining suspect. Amtrak service was also temporarily suspended between Boston and Providence, R.I.
Massachusetts State Police Superintendent Timothy Alben told reporters the situation is “grave.”
President Obama was briefed on the situation overnight, according to a White House official.
The MIT shooting on the Cambridge campus Thursday night was followed by gunfire and explosions in Watertown, about 10 miles west of Boston.
The MIT officer had been responding to report of a disturbance Thursday night when he was shot multiple times, according to a statement from the Middlesex district attorney’s office and Cambridge police. It said there were no other victims.
Information from CBS News and USA Today contributed to this report.