WACO, Texas (AP) -- A shooting involving rival biker gangs at a Central Texas restaurant has left nine people dead and some others injured.

Waco police Sgt. W. Patrick Swanton says eight people died at the scene of the shooting at Twin Peaks restaurant about noon Sunday and another person died at a hospital.

Swanton says the fight began with punches and then escalated to knives and firearms. It's not immediately clear if bystanders are among the dead.

The severity of injuries to others was not immediately known.

He says police were aware that gang members were gathering at the restaurant and officers were present when shots began.

Some of the officers fired on bikers as the shooting spilled from the restaurant into a busy parking lot. Patrons and bystanders dove for cover.

A photo from the scene showed at least two people wearing what looked like biker jackets on the ground. It was not clear why they were prone on the pavement. Police were standing nearby along with other people wearing biker jackets.