Oakland Robbers Ransack Jewelry Store, Wild Video Shows

A group of thieves smashed up an Oakland jewelry store, stealing valuables from the broken glass cases before a man with a shotgun chased them off ... and, it was all caught on video.

Eight people ran into Phuong Jewelry in Oakland's Chinatown neighborhood Wednesday ... bashing cases with hammers and making off with a ton of the store's pieces.

Check out the vid ... the first person walks in holding what appears to be a gun and aiming it at the store's owner, Diane Trinh, and another person, forcing them to drop to the ground -- before the other assailants start to smash in the cases.

After a few seconds, Diane runs to the back to get her 76-year-old husband ... who comes into the store with his own gun, chasing off the robbers who'd already grabbed a ton of jewelry.

Diane and her son, Tony, spoke with KGO-TV about the attack ... reportedly telling the outlet the robbers made off with between 85-90% of their inventory in the quick strike.

KGO-TV also says the business let its insurance lapse ... so the Oakland Chinatown Improvement Council's trying to raise money to help the family out during this tough time.

Crime in Oakland's becoming a serious issue for business owners ... as we reported, an In-N-Out and a Denny's in the city shut down citing rising crime rates, and several Taco Bells in Oakland are now drive-thru only to protect their employees.