San Francisco police today are seeking witnesses to a shooting outside a concert at the Regency Ballroom late Sunday that left a dozen people injured.
   
A man opened fire just before 10:15 p.m. at Van Ness Avenue and Sutter Street, shortly after the sold-out KMEL House of Soul concert ended, police said.

Police spokesman Sgt. Wilfred Williams said today that eight people suffered gunshot wounds and another four were injured by bullet or glass fragments.

Paramedics took some of the shooting victims to the hospital, while others were driven to hospitals by friends, Williams said. All of the victims are expected to survive.

Williams said an argument led to a fistfight between two people.

Two other people jumped in to help one of the combatants, and a fifth man then arrived and opened fire, he said.

Williams said the shooter, who fled on foot, is not believed to have ties to any of the people fighting.

He was described as a black man in his 30s wearing an unbuttoned white shirt with blue pinstripes, a white T-shirt, blue jeans and a baseball cap.

Witnesses who wish to remain anonymous can contact police at (415) 575-4444 or use the department's Text-A-Tip service by texting "tip411."