Police are looking for a man who allegedly assaulted a victim in North York with an unknown object.

The incident happened on June 15 in the Don Valley Village area, near Don Mills Road and Van Horne Avenue.

Toronto police said they were called to that area at around 5:30 a.m. following reports of a sexual assault.

Investigators say that a victim exited a TTC bus and was followed by a man, who allegedly grabbed them from behind and assaulted them with an unknown object before fleeing the scene.

They said that a passerby witnessed the incident and assisted the victim.

The suspect is described as an Asian male, 20 to 30 years old, and approximately five foot eight and 170 pounds. He was last seen wearing all black clothing.

Anyone with information is asked to contact police at 416-808-7474 or Crime Stoppers anonymously.