MONTREAL - The day after yet another firebombing in Montreal, police say they are making progress in determining who is responsible for the waves of arsons against Italian cafes and other city restaurants, but acknowledge they have much more work to do.

Speaking to the media on Tuesday afternoon, Commander Mario Lamothe said that officers believe there is a link between the establishments hit by firebombs and drug trafficking.

"More than 20 people were arrested because they were dealing drugs inside the cafes," said Lamothe,who leads the Montreal police Economic Crimes division.

"We know it's mafia-related."

According to documents handed out by police, 15 people were arrested for drug trafficking from Nov. 11 to Nov. 19 in St. Michel. Two more people were arrested on Nov. 24, and all had significant amounts of drugs including cocaine, hashish, amphetamines and contraband cigarettes.

Lamothe said that in recent months beat officers have visited more that 150 restaurants, stores and cafes, and that they will continue to meet with store owners.

Patrollers have been given a checklist of questions to ask, including determining how worried proprietors are about the threat of arson.

In November police arrested four people who are charged with arson and attempted arson, but more suspects are still at large.

Dozens of cafes, restaurants, and other stores have been attacked by Molotov cocktails this year.

In one of the more recent cases, arsonists attacked Cafe Danesi twice in two weeks.

The latest firebombing occurred Tuesday morning, at La Toca Grill on Henri Bourassa. Nobody was injured.

Police are urging anyone with information about the arson attacks, or any other crimes, to contact their Info-Crime line at 514-393-1133.