BREAKING- POLICE COMB WATERTOWN, MA NEIGHBORHOOD FOR GUNMEN AFTER MIT CAMPUS POLICE OFFICER SHOT AND KILLED- UPDATE: CHECHEN BROTHERS SAME INDIVIDUALS IDENTIFIED BY FBI AS SUSPECTS IN MARATHON BOMBING

AP Photo

Hours after an FBI press conference in which they showed photos and video of the two individuals considered suspects in the Boston Marathon bombing, a MIT police officer was shot and killed by assailants on campus. The shooting was followed by a robbery, carjacking and cross-town pursuit where the gunmen opened fire on police with guns and grenades before crashing their stolen vehicle in nearby Watertown, MA.

WCBV-TV said the suspects threw and detonated explosives during a car chase with police.

Police were working to apprehend a young male with a hat on who was reportedly pulling on vehicle doors, according to police scanner traffic.

An FBI official told Fox News early Friday that one person was in custody and an officer was down but said it was too early to tell if the police activity in Watertown or the MIT shooting were related to the Boston Marathon bombing.

Dozens of officers and National Guard members descended on Watertown shortly after the shooting outside a building on MIT's campus in Cambridge, according to the Associated Press.

Authorities were calling for somebody to get on the ground and put their hands up and a loud thud was heard after someone shouted "fire in the hole," the news agency reported.

Witnesses told The Associated Press they heard multiple gunshots and explosions at about 1 a.m. Friday. Dozens of police officers and FBI agents were in the neighborhood and a helicopter circled overhead.

State police spokesman David Procopio told news agency, "The incident in Watertown did involve what we believe to be explosive devices possibly, potentially, being used against the police officers."

Fox News reporters on the scene cannot yet confirm these reports.

Earlier Friday, Cambridge police and the Middlesex District Attorney's office said the MIT officer was responding to a report of a disturbance when he was shot multiple times late Thursday. He later died at a hospital. His name was not immediately released.

Procopio said the shooting took place about 10:30 p.m. outside an MIT building. The area was cordoned off and surrounded by responding law enforcement agencies, according to a posting on the university's website.

Procopio said authorities were searching for a suspect or suspects. No arrests have been made.

The university described the situation late Thursday as "active and extremely dangerous." People were urged to stay away from the Stata Building, a mixed use building with faculty offices, classrooms and a common area.

Officers from numerous agencies and reportedly exchanged gunfire and pursued the two suspects on foot- one of them was wounded and taken into custody while the other was still at large in the overnight hours. Police from Boston, Watertown, Cambridge, the MBTA, Boston College and the Massachusetts State Police quickly set up a perimeter and began an intensive search for the remaining suspect, with federal agents quickly arriving to aid in the search for the suspect and additional explosive devices he may have left in the area.

WFXT-TV and Boston Police commissioner Edward Davis had confirmed that the suspect in custody died at Boston's Beth Israel after the confrontation.

One suspect dead. One at large. Armed and dangerous. White hat suspect at large.
— Edward Davis (@EdDavis3) April 19, 2013

It is unclear whether or not the deceased suspect died from a gunshot wound or from one of the detonated explosive devices- an MBTA police officer is hospitalized after exchanging gunfire with the suspects after carjacking an SUV at a gas station adjacent to the MIT Campus in Cambridge.



The identities of the two bombers remain something of a mystery after conflicting reports overnight. Various social media users speculated that one of the bombing suspects is bore an uncanny resemblance to a Brown University student who has been missing for about a month, but NBC News indicated that the suspected bombers had unspecified foreign military experience.

FBI Photo

Police are urging area residents to remain indoors and only answer the door if they see a uniformed police officer knocking. Authorities have also made a decision to shut down MBTA service in the area to prevent the remaining suspect from fleeing or detonating any remaining explosives as people were waiting for trains or bus service.

4/19 UPDATE - FOX News and the AP have identified the fugitive bombing suspect as a 19 year old Chechen named Dzhokhar A. Tsarnaev who apparently entered the country legally and has been residing in Cambridge, MA for the last year. The slain suspect is reportedly his older brother.