Photo

Last Updated, 5:45 p.m. A Massachusetts Institute of Technology campus police officer was shot and killed near the campus in Cambridge, Mass.,Thursday night, authorities said.

The two men wanted in the Boston Marathon bombings are believed to have fatally shot a Massachusetts Institute of Technology police officer, Sean Collier, 26, in his patrol car, the Middlesex County district attorney’s office said.

Photo

The officer had responded to a report of a disturbance near Vassar and Main Streets, the Middlesex District Attorney Michael Pelgro said in a statement early Friday. He was found, the statement said with “multiple gunshot wounds” and taken to a hospital where he was pronounced dead.

M.I.T. said in an update on its campus alert Web site after midnight that the “shooter remains at large, police continue to search the campus,” and asked students to stay indoors until further notice.

At the campus, helicopters whirred overhead, and police cars were dotted through the streets. A crime scene was cordoned off, and at least one dog unit was on the scene.