Authorities are looking for a suspect who threw urine at a bus driver in the Bronx.

The NYPD says the male suspect was with a 5-year-old boy when he boarded the BX12 bus at White Plains Road and Pelham Parkway on Oct. 1 at 5:15 p.m. Police say the suspect had an argument with the driver, then threw a vial of urine in the driver's face when the bus arrived at Pelham Bay Station.

The suspect fled on foot with the child, cops say.

The bus driver was taken to the hospital for irritation to his face and eyes.

The suspect is a 20-year-old man who is about 5-foot-8 and 180 pounds, authorities said. Anyone with information on the alleged assault is asked to call Crime Stoppers at 1-800-577-TIPS.