Los Angeles ? The deadly gun and knife fight in a Nevada casino last weekend was just the latest battle in an increasingly bloody turf war in which several motorcycle gangs across the country have all lined up against the Hells Angels.

The bloodshed among the outlaw bikers began several months ago with the breakdown of a truce that had largely held for about a decade.

Police stand next to unidentified motorcycle gang members after a fatal brawl took place at the Hellraiser Ball 2002in Plainview, N.Y. Conflicts between Hells Angels and rival gangs are on the increase, law enforcement officials note.

At stake are turf and the drug trade that comes with it.

Law enforcement experts said they not sure exactly what set off the round of violence, but it has put the Pagans, Bandidos, Sons, Outlaws, Vagos and Mongols on the same side.

“You have the Hells Angels basically going up against virtually every other motorcycle club,” said Tim McKinley, a motorcycle gang expert with the FBI in San Francisco.

The rising tensions over the past few months had led Sonny Barger, the legendary founder of the Angels, to organize a “peace powwow” in the Arizona desert that was supposed to take place after the gathering of motorcycle enthusiasts in Laughlin, Nev., last weekend, Arizona police said.

But the peace conference was scuttled by the brawl between the Hells Angels and the Mongols inside Harrah’s Casino. Three bikers two Hells Angels and a Mongol died in the crowded casino and a Hells Angel was shot to death as he rode away from Laughlin.

Tensions are high because gang membership nationwide has expanded over the past decade and that has led to fights over turf, said Lt. Terry Katz, a motorcycle gang expert with the Maryland State Police.

The Hells Angels have more than 200 chapters worldwide and 1,800 to 2,000 members, about double the club’s membership of 10 years ago, according to McKinley. The largest rival gang is the Bandidos, with about 2,500 members.

The Hells Angels, founded 54 years ago in California, were mythologized as rebels without a cause by Hollywood in the 1950s and ’60s but showed their murderous potential at the Altamont music festival in 1969, when the Angels, hired as security guards at a Rolling Stones concert, stabbed an audience member to death and beat others. In recent years, as many Hells Angels entered middle age, the club has tried to polish its image with toy drives, food giveaways and support for Vietnam veterans.

The truce in the United States collapsed because many of the smaller gangs felt the Hells Angels were dictating the conditions, and they had had enough, said New Hampshire State Police Lt. Terrence Kinneen, former president of the International Outlaw Motorcycle Gang Investigators Assn.

In February, police in Revere, Mass., arrested 23 heavily armed Outlaws outside a club where the Hells Angels were gathered. Later that month, violence broke out between the Hells Angels and the Pagans on New York’s Long Island. The fight left one Pagan dead, five gang members shot, and five stabbed. One Hells Angel was charged with murder.

A turf battle in Canada between Hells Angels and rival gangs has killed more than 100 in the past decade, Katz said. In Scandinavia, Hells Angels and Bandidos have fought it out with guns and high-tech weapons, including rocket launchers.