According to Mission Mission. SFist, and the Chronicle, 20+ shots where fired outside of El Tin Tan, a bar popular with recent immigrants looking for work, on 16th between Mission and Valencia around 11pm last night.  Four of the victims are expected to survive, while one is in critical condition after being shot 12 times.  From the Chronicle:

The bar's front door was riddled by bullet holes, and gunfire shattered the glass front door of the Pancho Villa Taqueria next door to the bar.

A motive for the shooting was not immediately disclosed, and it was unclear whether the violence was linked to a recent spate of gang violence in the Mission District. San Francisco police have stepped up enforcement and patrols to combat an increase in stabbings and shootings connected to an ongoing rivalry between the Norteños and Sureños street gangs.

Sadly, the shooting occured 10 minutes after The Examiner published a story about how SFPD has calmed the violence in the neighborhood.

[photo via Mission Mission]