New York police said a 48-year-old man was shot and killed on Sunday on a subway train in Lower Manhattan, and investigators believe the attack was unprovoked.

The unidentified gunman fled when the train pulled into the next station, and remained at large on Sunday night,  New York City Police Department (NYPD) Chief Kenneth Corey said at a news briefing.

The suspect and the victim were not acquainted and had not interacted prior to the gunfire, police said. The victim, who was not identified by police, was pronounced dead at Bellevue Hospital shortly after the 11:40 a.m. shooting.