A police officer for the Massachusetts Institute of Technology was shot to death on Thursday night at the school's Cambridge campus, touching off a manhunt in a community on edge just days after the Boston Marathon bombing.

Police descended on a vehicle in the neighboring Watertown community later in the evening amid reports of gunfire and explosions, the ABC TV station in Boston reported. One suspect was in police custody, local media reported.

Reuters was not immediately able to verify the reports.

Police officers with weapons drawn, and people wearing FBI and ATF jackets could be seen in the live video.

It was not clear if the police activity in Watertown was related to the shooting at MIT, or if either was connected to the bombing of the Boston marathon, which killed three people and wounded 176.

David Procopio, a spokesman for the Massachusetts State Police, said that while he did not believe the MIT shooting was connected to the Boston Marathon bombing, "I can't say that with 100 per cent certainty at this time."

MIT early on Friday said that MIT police had determined that the suspect in the shooting was no longer on campus and it was now safe to resume normal activities. Massachusetts State Police and Cambridge police said they were assisting in the investigation.

Procopio said the motive for the shooting was not known and the investigation would be led by the Middlesex County District Attorney's Office after the death of the officer.

FBI Boston Special Agent Greg Comcowich said the office was referring questions about the shooting to Cambridge and MIT police. "I can tell you that we are aware of it however."

The shots on Thursday night were reported near Building 32, MIT said in an emergency statement warning students to "stay indoors and away from the area."

MIT police representatives could not be reached immediately for comment.-Reuters