Man knocked out during fight on SF Muni bus

Photo: Bill Hutchinson / The Chronicle 14 Muni passes by intersection of Mission and Ninth streets early...

A 59-year-old man was beaten unconscious on a Muni bus he was riding through San Francisco’s Tenderloin neighborhood after he got into a fight with a passenger, police said Friday.

The incident started around 5:50 p.m. Thursday when the bus driver heard a loud argument going on and pulled over near Market and Fifth Streets, said Officer Giselle Talkoff, a San Francisco Police Department spokeswoman.

All of the passengers exited except the victim, who the driver found unresponsive lying on the floor in about the middle of the bus, Talkoff said.

The man was taken to a hospital, where he was being treated for non-life-threatening injuries.

The driver told police she saw a man who appeared to be the assailant run off the bus. Police were searching for the suspect.

Jenna Lyons is a San Francisco Chronicle staff writer. Email: jlyons@sfchronicle.com Twitter: @JennaJourno