An Uber driver is accused of seriously injuring a passenger by bashing him on the head with a hammer in San Francisco’s Bernal Heights neighborhood, authorities said Friday.

Patrick Karajah, 26, of Pacifica pleaded not guilty Thursday in San Francisco Superior Court to charges of assault with a deadly weapon and battery with serious bodily injury. He is free on $125,000 bail.

Karajah allegedly picked up the victim and his two friends from a bar at about 2 a.m. Tuesday. While driving the two men and one woman to their destination, he got into a dispute with the victim over the route he was taking, according to court documents.

Karajah, who was driving for the basic UberX service, stopped near the intersection of Ellsworth Street and Alemany Boulevard and forced the victim and his friends to get out, according to documents.

Once the victim was out of the vehicle, Karajah struck him on the side of his head with a hammer, and then drove away, authorities said.

When police arrived, they reportedly found the victim slipping in and out of consciousness on the sidewalk, suffering from severe fractures and trauma to the head. Karajah was later arrested at his home in Pacifica.

“We take reports like this seriously and are treating the matter with the utmost urgency and care,” said Eva Behrend, an Uber spokeswoman. “It is also our policy to immediately suspend a driver’s account following any serious allegations, which we have done. We stand ready to assist authorities in any investigation.

“Safety is Uber’s No. 1 priority.”

In June, another driver for the company, 28-year-old Daveea Whitmire, was charged for allegedly striking a passenger.

Karajah’s attorney did not immediately return requests for comment. A person who answered the phone at Karajah’s home Friday declined to answer questions.

Vivian Ho is a San Francisco Chronicle

staff writer. E-mail: vho@sfchronicle.com Twitter: @VivianHo