PITTSBURGH (KDKA) – An Uber driver fired a shot in self-defense when he said four of his passengers assaulted him.

Pittsburgh Police say they responded to a report of an assault on the 300 block of Crafton Avenue around 2 a.m. Tuesday morning.

When they arrived, they met an Uber driver who told police he was assaulted by four men who were passengers in the car.

Police say the driver claimed he shot in self-defense, with his shot grazing a suspect in the head. That suspect was taken to the hospital in stable condition.

The other passengers ran, but police say they were later arrested on robbery charges.

Uber says its firearms policy prohibits “riders and their guests, as well as driver and delivery partners, from carrying firearms of any kind while using our app.”

Police are investigating.

Stay with KDKA for the latest on this developing story.