Update, 4/19/13, 3:20am
WATERTOWN, Mass. (AP) -- The FBI is investigating whether the shooting of a campus police officer at the Massachusetts Institute of Technology and gunfire and explosions in a nearby town are related to the Boston Marathon bombings.
A Massachusetts State Police spokesman says one person suspected in the gunfire and explosions has been accounted for and one is at large.
The FBI says it is working with local authorities to determine what happened.
The MIT shooting on the Cambridge campus Thursday night was followed by reports of violence in nearby Watertown, about 10 miles west of Boston.
A state police spokesman said early Friday there is a "strong possibility" the incidents are related.
Cab driver Imran Sais says he heard "a loud boom" while standing on a street corner at a police barricade across from a diner.
Update, 4/19/13, 1:05am
WATERTOWN, Mass. (AP) -- Police have converged on a neighborhood outside Boston where there were reports of explosives being detonated and police are telling reporters to turn off their cell phones.
Dozens of officers and National Guard members are in Watertown, where television outlets report that gunfire and explosions have been heard. A helicopter is circling overhead.
Authorities early Friday 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."
Reporters are being told to move away from the scene. A police officer told a reporter: "If you want to live, turn off your cell phone."
Earlier Thursday night a campus police officer was shot and killed at MIT and authorities were searching for the person responsible.
CAMBRIDGE, Mass. (AP) -- Authorities say a campus police officer at the Massachusetts Institute of Technology has died from injuries in a shooting on the campus outside Boston.
Cambridge police and the Middlesex District Attorney's office says the officer was responding to a report of a disturbance when he was shot multiple times. He later died at a hospital. His name was not immediately released.
State police spokesman Dave Procopio says the shooting took place about 10:30 p.m. outside an MIT building.
Procopio says authorities are searching for a suspect or suspects. No arrests have been made.
MIT police, Cambridge police and state police are involved in the investigation.
About 11,000 people attend the prestigious school.
The campus website said police were sweeping the campus and urged people to stay indoors.