Montreal police arrested nine suspects Thursday in connection with a series of firebombings that damaged more than a dozen Italian cafés starting last fall.

Five of the suspects are scheduled to be arraigned at the Montreal courthouse later today, police said in a statement. One of them is a minor.

They face charges of arson, mischief, armed robbery, illegal possession of prohibited firearms, conspiracy and possession of materials to commit arson.

Police linked the men arrested to local street gangs, but said they do not necessarily belong to the groups.

The investigation, dubbed Project Arcane, remains underway, since many of the fires are still unsolved, police told reporters.

At least 18 Italian businesses, many of them cafés, were hit with Molotov cocktails between last Sept. 22 and this Jan. 24, according to police. No one was hurt in the attacks.

Another suspect, 18-year-old Mickendy Demosthene, was arrested in December. He was charged with arson and break-and-enter.

Police have long suggested street gangs could be involved in the incidents. Other theories mentioned the possibility of a Mafia turf war, or a rare collaboration between gangs and mob.