Montreal (AFP) - One of the busiest border crossings between Canada and the United States reopened Friday, after authorities after being evacuated following a bomb threat, Canadian officials said.

Canadian border services agency said in a tweet that they reopened the Saint Bernard de Lacolle POE Highway 15 in Quebec, after a nearly four hour interruption.

The Saint Bernard de Lacolle checkpoint sits about 60 kilometers (37 miles) south of Montreal on the border between Quebec province and the US state of New York.

Passage in both directions had been blocked shortly after 9:00 am (1400 GMT) following a "threatening telephone call aimed at customs," according to Ingrid Asselin of Quebec's national police agency.

More than two million visitors cross at the Saint Bernard de Lacolle checkpoint each year.

During the closure, Canadian border services directed travelers to use other nearby border crossings.