A gunman has shot a sheriff's deputy and around 10 other people in a country and western bar and dance club in southern California, authorities said.
Ventura County sheriff's Captain Garo Kuredjian said he could not confirm whether any of those shot on Wednesday night were dead.
He described the situation as still active.
"We're still looking for the shooter," Mr Kuredjian said. "We can't confirm that the shooter is in custody."
He said hundreds of people were in the Borderline Bar & Grill in Thousand Oaks at 11.20pm, and shots were still being fired when officers arrived.
'It was chaos'
It was college night and country two-step lessons were being offered on Wednesday at the Borderline, according to its website.
It has been "quite some time" since there was a shooting of any kind in Thousand Oaks, a city of about 130,000 people around 40 miles west of Los Angeles.
Nick Steinwender, student body president at nearby California Lutheran University, rushed to the scene when he heard about a shooting at the bar where he knew friends and fellow students were.
"It was chaos, people jumping out of windows, people hopping over gates to get out" Mr Steinwender told KABC-TV.
He said he heard from people inside who were hiding in toilets and the attic of the bar.