A forest fire is seen in California 2009. A wildfire engulfed the town of Slave Lake in western Canada, forcing the evacuation of its 7,000 residents at the start of the forest fire season, authorities said Monday.

A wildfire engulfed the town of Slave Lake in western Canada, forcing the evacuation of its 7,000 residents at the start of the forest fire season, authorities said Monday.

Two fires had razed 2,900 hectares of nearby forests before suddenly shifting towards the town and three others in the vicinity that are now threatened.

"We didn't have any warning of how quickly the could spread," Slave Lake mayor Karine Pillay-Kinnee told public broadcaster CBC. "We had substantial gusts of wind that transferred the fire across highways quickly into the town."

Many homes and buildings have been razed to the ground. Television images showed rows of buildings engulfed in flames as 1,000 battled the blazes, trying to save what little remains of the town located 250 kilometres (155 miles) north of Edmonton, Alberta.

Authorities said there are 116 fires burning in the province, including 39 that are out of control.