Police are looking for a man who touched a sleeping woman’s buttocks on a southbound N train Monday in Brooklyn.

The 25-year-old woman was sleeping on the train near the Atlantic Avenue - Pacific Street station around 5:30 p.m. when the suspect began touching her buttocks, the NYPD said.

A witness woke the woman up and told her what had happened and the suspect fled.

Anyone with information is asked to call Crime Stoppers at 800-577-TIPS.