MONTREAL - Toronto's police chief says Canadian authorities should be concerned about the ties street gangs have to criminal groups abroad.

Bill Blair, who was attending an international conference in Montreal on street gangs, says the links pose a threat to Canadian communities by helping gangs to gain access to guns and drugs.

Blair's comments in an interview today with The Canadian Press reflect an increasing awareness about the international criminal networks that work with the country's gangs.

The head of research for Montreal police, who was also attending the conference, says the force is undertaking a major study to track what happens to gang members after they're deported.

Michelle Cote says it's important to understand whether criminals maintain their connections to Canada after leaving the country.

Hundreds of police officers, experts and policy-makers are attending the week-long conference.