Police in Cambridge, Massachusetts, are searching for a for a gunman who fatally shot a police officer on the campus of Massachusetts Institute of Technology late Thursday evening.
Campus police said the police officer was shot multiple times while responding to a disturbance on campus and later died of his wounds in the hospital.
A large area of campus was cordoned off as security forces fanned out to look for the suspect. Students were initially advised to stay indoors during the search, but the university has since lifted that warning.
Meanwhile, in nearby Watertown, police have detained at least one person in a large police operation featuring blaring sirens, multiple police vehicles, and helicopters. VOA's Carolyn Presutti, in Watertown, says a bomb squad and the FBI are now on the scene.
It is unclear whether the operation is connected with either the campus shooting or with Monday's Boston Marathon bombing, which took place just across the Charles River.
As the operation continues, Boston police have advised Watertown residents to remain indoors.