NEW YORK (AP) -- New York City police are questioning a man in the killing of an on-duty bus driver who was stabbed in front of horrified passengers.

No charges have been filed, but a person of interest is being interviewed at a police precinct.

The victim, 46-year-old Edwin Thomas, was driving the bus in Brooklyn when the attacker got on shortly after noon Monday.

Police say the man swiped an invalid fare card and sat down before asking for a transfer slip. When Thomas told the man he didn't pay for the ride and couldn't get a transfer, the man punched him in the head and stabbed him in the torso.

Thomas was rushed to a hospital, where he died. The attacker ran away.

(Copyright 2008 by The Associated Press. All Rights Reserved.)