Police warn people in Boston suburb not to open doors

WATERTOWN, Massachusetts (Reuters) - Massachusetts State Police warned people in the Boston suburb of Watertown not to open their doors and said they would conduct a door-to-door, street-by-street search due to what it called a fluid situation.

It was not immediately clear what connection the warning may have to the Boston Marathon bombings.

A massive police operation was under way in Watertown after a university police officer at the Massachusetts Institute of Technology was killed and one man was taken into custody in Watertown.

(Reporting by Scott Malone; Editing by Daniel Trotta and Lisa Shumaker)