With one of the Boston Marathon bombing suspects dead and the other suspect on the loose, state and local officials asked people in Boston and several inner suburbs Friday morning to remain at home with doors locked.

“There is a massive manhunt underway. A lot of law enforcement involved in that,” Gov. Deval Patrick told reporters from a televised briefing in Watertown.

Read: A summary of the overnight events in Cambridge and Watertown from Universal Hub.

An MIT police officer was killed Thursday night, and sometime after that an MBTA officer was seriously wounded and is now in surgery, Patrick said.

Patrick said suspect 1 is dead and suspect 2 is at large.

Early Thursday evening, federal authorities unveiled photos of suspects in the marathon bombing that killed three and injured more than 170. Suspect 1 wore a black hat; suspect 2 wore a white hat and was observed placing a backpack at the site of the second explosion Monday, in front of the Forum restaurant on Boylston Street. Both were deemed armed and dangerous by the FBI.

"No one should approach them. No one should attempt to apprehend them, except law enforcement," Boston FBI Special Agent in Charge Richard DesLauriers said on Thursday, before the attacks on police. "Do not take any action on your own. If you see these men contact law enforcement."

Patrick advised residents of Watertown, Cambridge, Waltham, Newton, Belmont and all of Boston to remain indoors, and said MBTA service has been suspended.

“To assist that we have suspended all service on the MBTA, our public transit service, and that will continue until we think it’s safe to open all or some of that,” Patrick said. “We’re asking people to shelter in place. In other words, to stay indoors with their doors locked and not to open the door for anyone other than a properly identified law enforcement officer.”

Around 10:20 p.m. Thursday evening, police heard reports of shots fired on the Massachusetts Institute of Technology campus, right across the Charles River from Monday’s marathon bombings. At 10:30 p.m., an MIT police officer was found shot in his vehicle by Vassar and Main streets in Cambridge, according to a press release from Acting Middlesex District Attorney Michael Pelgro. The officer was shot multiple times, was taken to Massachusetts General Hospital and pronounced dead, according to the DA.

Soon after the shooting, which police believe involved two males, authorities received a report of a car-jacking along Third Street in Cambridge. Two men had allegedly car-jacked a vehicle, holding a man for a half hour before releasing him unharmed at a gas station along Memorial Drive.

As police pursued the car towards Watertown, bombs were reportedly thrown from the car, and the suspects and police exchanged gunfire at Dexter and Laurel streets in Watertown. During the pursuit an MBTA officer was injured and one of the suspects was taken to a hospital where he was pronounced dead, according to the DA.

“The Massachusetts State Police Bomb Squad is assessing and removing any potentially explosive devices that may have been thrown on the street in Watertown by the suspects,” the DA’s press release said.

At 8:20 a.m., Boston Mayor Thomas Menino’s administration released a citywide update: “The City of Boston is urging City-wide shelter in place. As this investigation unfolds we are advising all residents, citywide, to shelter in place. Please understand we have an armed and dangerous person(s) still at large and police actively pursuing every lead in this active emergency event. Please be patient and use common sense until this person(s) are apprehended. We will continue to update the public with more information as it becomes available. All MBTA service remains suspended at this time.”