Investigators were trying to determine on Monday what triggered a running gun battle at a weekend dance staged by a Central California motorcycle club that left one man dead and 13 people wounded as hundreds of partygoers scrambled for cover.

Shots were still being fired early Saturday around the Soul Brothers clubhouse near Fresno when the first of more than 100 law enforcement officers arrived, the Fresno County Sheriff's Office said.

About 500 people were inside the warehouse-like building when the shooting started.

The shooting quickly spilled into a street outside the club as partygoers sought safety, sheriff's spokesman Chris Curtice said.

No arrests have been made, and Curtice declined to discuss whether investigators had any suspects.

"Detectives are following up several leads," he said.

All the injured people were expected to survive, though some suffered serious wounds. The department didn't release their names. It initially reported a dozen were hurt.

Residents in the area said they were awakened by gunshots and roaring motorcycles.

"As a mother, of course you're scared to hear gunshots so close to your house, definitely I was scared," Christina Aranda told KFSN-TV.

The Fresno County coroner has identified the dead man as 18-year-old Dejuan Gladney. The coroner didn't list a hometown.

Gladney and several injured people were found in the clubhouse in an unincorporated neighborhood of Fresno County called Calwa.

Large gatherings of bikers descend on Fresno twice a year — once in the spring and again in the fall, the Fresno Bee reported (http://bit.ly/GEKzrW ). The gatherings frequently turn violent, the newspaper said, but police have blamed gangs for starting some of the violence rather than bikers in clubs.

No representatives of the Soul Brothers could be reached at the clubhouse.

Previous newspaper reports say Soul Brothers was formed in 1967 in East Palo Alto as a multi-racial club before moving to Stockton then Fresno. The club also has a Las Vegas chapter.