An unmarked unit and officers chase a suspect up Frank Norris, off Polk Street between Bush and Pine. Photos by Bryan Goebel. A high-speed police chase of a stolen black SUV began in Tiburon and ended on Polk Street in San Francisco this afternoon, a frightening scene that sent pedestrians running and bicyclists scurrying to the sidewalk. A witness on the scene said a bicyclist traveling down Pine Street near Polk was injured and transported to a nearby hospital.
The witness, who would only identify himself as Stearn, was standing outside Kimo's bar when he saw the bicyclist riding down Pine Street, just as a convoy of CHP, SFPD and unmarked units were thundering to the scene.
"He made the corner and three CHP cars were coming down the street. I saw the guy swerve to miss the CHP car, and about that time, a Federal Expresss truck drove by so I couldn't see whether the cop car hit him or not. But the guy went down and another CHP car, this one across the street, pulled over and got the bicyclist out of the way by the time the third one passed through. And then once the CHP helicopter and everything was out of the way then an ambulance came and got him."
CHP Officer Mary Ziegenbein of the Marin County division confirmed a bicyclist was injured "trying to move out of the way" and transported but was not hit by a CHP unit. She claimed his injuries were minor, mostly to his chin. Witnesses described the bicyclist as a man in his 20s riding a red mountain bike.
More pics and details below the break.
The chase angered many pedestrians in the area, who questioned why police need to be racing through city streets at speeds that sometimes reached 65 mph (according to a KCBS reporter on the scene) for a stolen vehicle. "I wish they would respond to stabbings in the alley like that," said a merchant who didn't want to be identified.
Ziegenbein said the maximum speed reached on Polk was 35 mph "due to the heavy traffic there."
The stolen SUV was recovered, but the suspect was not arrested. According to Bay City News:
The vehicle had been reported stolen in San Francisco, and was located at about 3 p.m. because of LoJack, an electronic device attached to the vehicle, a CHP dispatcher said. The CHP pursued the vehicle across the Golden Gate Bridge into San Francisco where it was recovered.
Updated 6:49 p.m.
The ambulance you see in the distance is arriving to pick up an injured bicyclist, unbeknowst to me at the time. 
A CBS5 news van blocks the sidewalk to cover the action. 
