RICHMOND, Calif. (AP) — Police are seeking the motive for a deadly shooting at a San Francisco Bay Area house party during the weekend.

Police say more than one person walked up and fired into the gathering late Sunday night in Richmond. Two victims died at the scene, a third died at a hospital and five others were wounded.

Police say the party was advertised on Facebook and most of those who attended don't know each other. It was the second mass shooting in the Bay Area during the weekend.

Oakland police say a shooting that killed one person and wounded seven on Saturday appeared to be gang-related.