AUTHORITIES say at least 11 people including a sheriff’s deputy were shot after a gunman opened fire at a popular bar in Southern California.

Police told the Los Angeles Times that at least 30 shots were fired at the Borderline Bar & Grill in Thousand Oaks on Wednesday night (local time), which is about 40 miles west of Los Angeles.

According to Fox News the club was hosting a college night.

Police have told local media the suspect is dead.

The mayor of Thousand Oaks said the suspect had been “engaged and neutralised”.

ABC 7 is reporting some of the people who were at Borderline were also at the Route 91 Harvest Festival in LA, the scene of the worst mass shooting in modern US history.

Ventura County Sheriff’s Office Capt. Garo Kuredjian said at a news conference early Thursday that the sheriff’s deputy was taken to a hospital.

He could not immediately provide information on the extent of the victims’ injuries.

The sheriff’s spokesman said the responding deputies could hear gunshots as they arrived on scene.

Authorities are still treating it as an active shooter scene.

Officers at the scene indicated that soon after the gunfire erupted, victims were running to a nearby gas station to get medical help.

There are reports some used chairs to break windows inside the bar to escape.

The initial report at 11.20pm local time indicated that a man had opened fire with a semi-automatic gun.

Law enforcement and emergency crews were flooding the scene - including the FBI and bomb squad.

Live video posted by KABC-TV of Los Angeles showed aerial footage of armed officers entering the nightclub and numerous police vehicles outside.

As officers were responding, there were additional reports of gunfire.

A witness told ABC7: “I was at the front door talking to my stepdad. I heard these big pops.

“There were three or four and I hit the ground. The security guard was dead and the man had a handgun.

“The gunman had glasses and a black jacket. He had a big hand gun.”

Another witness said: “This maniac came in. Threw in smoke to confuse people and opened fire on the dancefloor. He’s taken many young lives”.

Authorities urged the public to avoid the area.

Borderline Bar & Grill originally opened in Malibu in the 1980s, but moved to Thousand Oaks in 1993, according to its website.

The bar is described as the county’s “Largest Country Dance Hall & Live Music Venue” and boasts 2500 square feet of open dance floor.

More to come