One of the busiest crossings along the U.S.-Canadian border has been closed as authorities in Quebec investigate a possible bomb threat.

A spokesman for Canada Border Services Agency tells the Canadian Press that the crossing received a threatening phone call around 9 a.m. Friday that mentioned an explosive device at St-Bernard-de-Lacolle, across the border from Champlain, New York.

Buildings on the Canadian side have been evacuated as a precaution and the border remains closed as provincial police, the Royal Canadian Mounted Police and firefighters search the area.

Officials with the U.S. Customs and Border Protection say it's being handled by Canadian investigators.

Southbound traffic in Quebec is being diverted to adjacent crossings as is northbound traffic on New York's Interstate 87.

It's unclear when the crossing will reopen.