ONLY ON 7: Video shows shootout between two cars in San Francisco

SAN FRANCISCO (KGO) -- San Francisco police are investigating a high-speed shootout that involved two cars Sunday morning.[br /][br /]Police say two cars exchanged gunfire on Polk Street around 9:30 a.m. Sunday morning. Witnesses say they heard at least 13 shots exchanged between the cars.[br /][Ads /][br /][twitter ID="863811186499833856" /][br /][br /]One car went north on Polk Street and officers did not find it when they arrived, police said.[br /][Ads /][br /]Officers located bullet casings in the area. No one reported being injured.[br /][br /]Neighbor Michael Kelly soon realized it was much more. Kelly's home security camera captured a gray sedan being fired on from a red BMW coupe during the high speed chase down Polk Street, from Lombard to Bay Street. "I guess I heard 10-11 shots," Kelly said.[br /][br /]Kevin O'Donnell saw the action from his apartment window. "I saw two cars side by side blow through the stop sign," O'Donnell said.[br /][br /]Police are reviewing surveillance video to gather more evidence.[br /][br /][url HREF="https://twitter.com/CornellBarnard" TARGET="" REL=""]Click here [/url]to follow Cornell Barnard on twitter for the latest updates.[/b]