WACO, Texas -- A deadly weekend shootout involving rival motorcycle gangs apparently began with a parking dispute and someone running over a gang member's foot, police said Tuesday.

Waco police Sgt. W. Patrick Swanton said an uninvited group appeared for Sunday's meeting of a loose confederation of biker gangs at a restaurant.

One man was injured when a vehicle rolled over his foot. That caused a dispute that continued inside the restaurant, where fighting and then shooting began, before the melee spilled back outside, Swanton said.

Authorities offered few details. It was not clear which gang was responsible for running over the biker's foot, or to which gang the aggrieved biker belonged.

When the shootout was over, nine people were dead and 18 wounded.

Police have said five biker gangs from across Texas had gathered, in part to settle differences over turf.

Jimmy Graves, who described himself as an ambassador for the gang known as the Bandidos, disputed that claim, saying the groups had planned to discuss laws protecting motorcycle riders and other topics such as trademarks for club logos.

But he acknowledged differences with other groups, such as the Cossacks, have been "simmering and brewing."

Another biker named Johnny Snyder said he was at the restaurant for a quarterly meeting to talk about legislative issues.

Snyder, a long-haul trucker, declined to describe what he saw inside the restaurant, saying he was only concerned with "not getting shot."

He is vice president of the Boozefighters Motorcycle Club in Waco, a group Snyder said does charity events and family gatherings and is not a criminal gang.

About 50 weapons were confiscated, mostly knives and firearms, and Swanton said more than 100 weapons may be found once authorities are done analyzing the crime scene at the Twin Peaks restaurant, which is part of a national chain that features waitresses in revealing uniforms.

Preliminary autopsy results showed all nine of the dead were killed by gunshots. Many were hit in the head, neck, chest or torso. Most of the men were in their 40s, but they ranged in age from 27 to 65, according to reports by a McLennan County justice of the peace.

Police have acknowledged firing on armed bikers, but it was unclear how many of the dead were shot by gang members and how many were shot by officers.

Of the injured, seven remain hospitalized. Swanton, who has been virtually the sole source of law enforcement information on the fight, described their conditions as stable.

He said the investigation is being hampered by witnesses who "are not being honest with us."

Police are concerned the brawl will invite retaliation and more violence, Swanton said.

"We would encourage them to try to be a little peaceful and let the bloodshed stop," he said.

About 170 bikers have been charged with engaging in organized crime. Swanton said more arrests are likely.

Katie Rhoten, whose husband, Theron Rhoten, was taken into custody, said he told her by phone from jail he and two other members of a motorcycle club called Vice Grip had just pulled up the restaurant.

"They got off their bikes, and bullets were ricocheting all around them, so they ducked and ran for cover," she said.

When her husband, a mechanic from Austin, and the others went back to retrieve their motorcycles, they were detained by police.

"They were told they were being held for questioning and released, and they sat in the parking lot for three, four, five hours."

Then, she said, police "changed their mind and arrested everybody on the scene."

Officers took into custody all sorts of "nonviolent, noncriminal people. I mean they got the Bikers for Christ guys in there."

In a memo dated May 1, the Texas Department of Public Safety warned about increasing violence between the Bandidos and the Cossacks.

The bulletin said the tension could stem from Cossacks refusing to pay Bandidos dues for operating in Texas and for wearing a patch on their vest that claimed Texas as their turf without the Bandidos' approval.

"Traditionally, the Bandidos have been the dominant motorcycle club in Texas, and no other club is allowed to wear the Texas bar without their consent," the bulletin said.

The bulletin said the FBI had received information the Bandidos had discussed "going to war with Cossacks." It outlined several recent conflicts between the two groups, including one in March when 10 Cossacks forced a Bandido to pull over along Interstate 35 near Waco and attacked him with "chains, batons and metal pipes before stealing his motorcycle."

That same day, a group of Bandidos confronted a Cossack member fueling up at a truck stop in Palo Pinto County, west of Fort Worth, the bulletin said. When the Cossack member refused to remove the Texas patch from his vest, the Bandidos hit him in the head with a hammer and stole it.

The Texas Department of Public Safety declined to release the bulletin to The Associated Press.

There are other documented instances of violence between the groups.

Last March, two members of the Bandidos were indicted in connection with the stabbing of two Cossacks at an Abilene steakhouse.

And in December, three Bandidos were arrested for a shooting at a Fort Worth motorcycle bar that left one dead and two others wounded. Fort Worth police said the victims were known members of a criminal motorcycle gang.

The Bandidos "constitute a growing criminal threat," the Justice Department said in a report on outlaw motorcycle gangs. The report said the Bandidos are involved in transporting and distributing cocaine and marijuana and in the production and distribution of methamphetamine.