Waco Texas shootout: Why the Bandidos and Cossacks biker gangs went to war at Twin Peaks

A shootout between rival motorbike gangs in Texas has left nine people dead in what police described as the "most violent crime scene" they had ever seen.

The gunfire first broke out inside the Twin Peaks "breastaurant" (known for its bikini clad waitresses) in Waco before spilling out into the car park.

At least 18 people were also injured during the incident from either gun shot or knife wounds. Police estimated around 100 weapons have been recovered from the scene.

Officers believe up to five gangs may have been involved in the shooting, with the Bandidos and Cossacks biker gangs said to have been at the centre.

McLennan County Sheriff Parnell McNamara said police believe all nine people who were killed in the shooting were members of the Bandidos or Cossacks gangs.

The rivalry between these two gangs is said to date back to at least 2013, with president of the Abilene, Texas chapter of the Bandidos, Curtis Jack Lewis, being arrested in November 2013 on suspicion of stabbing two members of the Cossacks outside a restaurant.

'The people our parents warned us about'

The Bandidos gang was first formed in 1966 in Texas by Don Chambers and is estimated to have more than 2,400 members in 210 chapters across the world.

The gang, whose motto is "We are the people our parents warned us about", have been classified as an outlaw gang by the FBI.

The FBI describe the Bandidos as a gang who are "are involved in transporting and distributing cocaine and marijuana and are involved in the production, transportation and distribution of methamphetamine".

In 2014, the Texas Department of Public Safety classified the Bandidos as a "Tier 2" threat during a gang assessment, the second highest rating.

In Scandinavia, the Bandidos were involved in a turf war with the Hells Angels in what was known as the Great Nordic Biker war.

The feud, which lasted between 1993 and 1997, resulted in 11 people dead, 74 attempted murders and 96 members wounded. The fighting included several shootouts, car bombs and even an anti-tank missile fired at a prison cell holding a Bandidos gang member.

In 2006, the group were involved in what police described as "internal cleansing" within the gang, resulting in the deaths of eight people. Six men, including member of the Toronto chapter Wayne Kellestine, were convicted in the mass shooting which occurred in south-western Ontario, Canada.

'We take care of our own'

The Cossacks were formed in Texas in 1969 and are believed to have allied with the Hells Angels in recent years in order to team up against the Bandidos.

The group have also taken to wearing a Texas patch on their clothing in what Steve Cook, executive director of the Midwest Outlaw Motorcycle Gang Investigators Association, described as "basically a slap in the face to the Bandidos" in an interview with Vox.

"We knew the tensions with the Cossacks were as high as they'd ever been," Cook said. "I don't think anybody could have forecasted it to the degree that it happened."

Their club patch features a nomadic horseman and warrior, which the group claims represents how Cossacks were "always on horseback [and] always ready to fight... Today, in modern times we traded our horses for motorcycles", according to book The One Percenter Encyclopedia: The World Of Outlaw Motorcycle Clubs.

The Cossacks, whose motto is "We take care of our own", also claim to be one of the biggest motorcycle clubs in Australia.

At least, three other motorcycle gangs were involved in the Twin Peaks carnage -bikers with patches from The Veterans, Leathernecks and Scimitars were spotted in the aftermath - milling around with Cossack members - suggesting that a lethal alliance against the Bandidos has emerged to continue the warring across the Texas badlands.