Quebec police arrested more than 20 people suspected of colluding to monopolize the province's tinted window business.

Police fanned out across central Quebec Wednesday morning, raiding several businesses and other locations in Montreal, Trois-Rivières and the Lanaudière region.

The 23 suspects arrested Wednesday are all involved with X-Vitres Tintées, a tinted window company in Repentigny. Police allege that more than 600 car dealerships across the province were harassed and intimidated in an effort to control the market.

"They [would offer] at first to work for them, or to buy their stores," said Quebec provincial police spokesman Sgt. Gregory Gomez del Prado.

Dealerships who refused were pressured in various ways, ranging from threats of violence to assault, vandalism and arson, del Prado said.

Police are still looking for the leader of the alleged ring, Yannick Larose, said del Prado.

Police believe the suspects have links to organized crime and were allegedly involved in marijuana production and cocaine trafficking.

The suspects face more than 140 charges including intimidation, extortion, armed robbery, aggravated assault and drug trafficking.

Wednesday's raids capped a two-year investigation launched after car dealership owners complained to police.