Police are asking for the public’s help identifying someone who robbed a 14-year-old at knifepoint on an N train in Bensonhurst.

Investigators say the man pulled a knife on the boy at the 20th Avenue subway station and demanded his jacket on Jan. 22.

The man took the jacket and fled on foot in an unknown direction. The boy was uninjured.

Anyone with additional information is urged to call 1-800-577-TIPS.