DENVER - One of the nation's fastest-growing motorcycle clubs is composed largely of military, police officers, and prison guards. It also embraces the regalia and traditions of outlaw biker gangs - a choice that has provoked deadly clashes with other groups.

The Iron Order club insists it is a law-abiding, charitable brotherhood of family men who just like to ride. But experts say its members are increasingly becoming entangled in violence with other biker groups, blurring the line between professionals who are sworn to uphold the law and a biker culture with a long history of criminal activity.

"It's almost like they are playing dress-up on the weekend and acting out what their perception of an outlaw gang is," said David Devereaux, a spokesman for the National Council of Clubs, which represents hundreds of motorcycle groups. "They create aggressive situations with other motorcycle clubs in opposition to the culture."

The latest skirmish happened Saturday, when the Iron Order and the Mongols motorcycle club clashed in a brawl that left a Mongols member dead.

The two groups blame each other for inciting the violence at the Colorado Motorcycle Expo, a gathering of biker groups from across the country. Police are not sure what set off the fight, which left seven other people shot, stabbed or beaten. More than one person fired a weapon during the melee, including a Colorado Department of Corrections officer who wore patches that clearly identified him as a member of the Iron Order.

No one has been arrested, adding to the frustration of other groups that complain Iron Order members pick fights, then use their law enforcement connections to avoid prosecution.

It's not uncommon to for law enforcement to join motorcycle clubs. Some groups exist exclusively for police, such as the Blue Knights, which has almost 20,000 members and performs community services year-round. A source of friction is that the Iron Order consists of both law enforcement and other professions, and it adopts emblems more common to well-established gangs, according to experts.

The Iron Order says its members have lawfully defended themselves during confrontations provoked by other groups that feel threatened by the club's rapid growth and its open disregard for time-honored rules of motorcycle culture.