Nine people were dead and an unknown number of others were injured, though no police officers were reported hurt.
Police were reportedly already at the scene due to a fight between the bikers inside the Twin Peaks restaurant when the shooting started. The fight apparently started with fists, then spilled out to the parking lot where it escalated to chains, knives and guns, police told KWTX.
The station reported that police were responding to other scenes around the city on Sunday afternoon, including a truck stop where a large number of bikers had gathered.
A district attorney warned two weeks ago that trouble had been brewing between bikers at the restaurant for some time, and police said they'd been working with management at the restaurant to try to prevent violence between rival bikers.