Canadian police arrested five people on murder charges Monday and said that eight men found stuffed inside vehicles on a farm over the weekend were affiliated with a biker gang.

Police called the killings "an internal cleansing" of the Bandidos motorcycle gang and said that the eight victims suffered gunshot wounds. Their bodies were found Saturday on a farm in Shedden, Ontario, about 90 miles northeast of Detroit.

Police on Monday searched a modest, two-story farmhouse owned by a gang member near the site where the eight men were found dead, stuffed inside abandoned vehicles in one of Canada's biggest mass murders in a decade.

Police set up a roadblock around the farmhouse, about six miles from where the bodies were found in four vehicles deserted in a farmer's field Saturday morning.

The gangland-style killings are the biggest mass murder in Canada since spurned husband Mark Chahal went on a shooting rampage in Vernon, British Columbia, killing nine people, including his estranged wife and himself in 1996.

Toronto-based organized crime expert Antonio Nicaso told The Associated Press that he learned from a reliable source that three members of the Bandidos have been missing since Friday. He said there were 12 members in the group.

Nicaso said the Bandidos were not that big or influential in Canada, but they are the major competitor of the Hells Angels motorcycle gang in the United States.

"If it is confirmed that the eight bodies were all members of the Bandidos you could say that someone decided to erase the Bandidos from the biker map," Nicaso said.

He said all messages of condolences had been taken off the Bandidos Web site, leading him to speculate that the murders may have been an inside job by club members.

The eight victims knew each other and were all from the Toronto area, police have said.

The rural area where the bodies were found has had problems with motorcycle gangs in the past, but is generally considered low-crime compared with other parts of Canada, in particular Quebec, where biker violence is more common.

"This is how they deal with disputes. They don't go to court. They don't print snotty lawyers' letters. This is what happens," law enforcement consultant Chris Mathers told the AP.

"It is shocking for it to happen all at one time," Mathers said. "The fact that they were all killed at one time is significant. ... It certainly sends a message."

Mathers, a former undercover Royal Canadian Police officer who now runs a consulting firm in Toronto, said the Bandidos and the Hells Angels have absorbed other biker groups in Canada over the year and he doubted there would be retaliation.

"It's probably hard to retaliate when most of your membership has been decimated," Mathers said.

Police found the bodies after a call from the property owner, who police said they did not consider a suspect. Mary and Russell Steele told Global News that the vehicles were not there when they took the road home the night before.

They said they called police Saturday morning after looking inside one of the vehicles and not being able to see anything because of a blanket covering the back window.