Authorities Sunday were investigating what touched off a wild "running gun battle" inside and outside a Fresno motorcycle club's annual dance, leaving one man dead and a dozen others wounded.

Shots were still being fired at 2 a.m. Saturday when the first of more than 100 law enforcement officers arrived at the Soul Brothers clubhouse near Fresno, the Fresno County Sheriff's Office said.

The gunfire erupted during the Soul Brothers' annual dance, which draws bikers and other motorcycle clubs from all over the state. About 500 people were inside the warehouse-like clubhouse when the shooting started.

The shooting quickly tuned into "a running gun battle" in the street outside the club, and hundreds of partygoers were running for cover when the first officers arrived, sheriff's spokesman Chris Curtice said.

Despite briefly detaining and questioning about 100 people, authorities have yet to make an arrest.

The Fresno County coroner identified the dead man Sunday as Dejuan Gladney, 18. The coroner didn't list a hometown.

Gladney and several injured people were found in the clubhouse, which is in an unincorporated neighborhood of Fresno County called Calwa. Another victim was on a nearby street.

Curtice said the injuries ranged from minor to "extremely serious." Authorities have not released the names of the people who were wounded.

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

The club's website was inoperable Sunday and no representative could be reached at the clubhouse.

Old 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, whose phone rang unanswered Sunday.