Police are searching for a man they say sexually assaulted a city bus driver in the Bronx.

The assault occurred at about 3:30 p.m. on May 15 aboard the Bx18 bus, police said. The suspect engaged the female driver in conversation before assaulting her, then running away at Undercliff Avenue and 171st Street. 

The suspect, who appeared to be in his 30s, had a scar under his left eye, according to police. 

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