(Reuters) – Canadian energy producers were hit with fresh disruptions on Tuesday after a massive wildfire burning around the oil sands hub of Fort McMurray, Alberta, shifted north, forcing the evacuation of about 4,000 people from work camps.

Suncor Energy Inc, one of the area’s biggest operators, said early Tuesday that it started a staged and orderly shutdown of its base plant operations as a precautionary measure.

Suncor said there had been no damage to its assets and that it had enhanced fire protection around the facilities.

Suncor and Syncrude Canada late Monday confirmed they had evacuated workers from the affected area.

The sudden movement of the fire prompted the evacuation of some 4,000 people from work camps outside Fort McMurray, with all northbound traffic again cut off at the city, the Regional Municipality of Wood Buffalo said on Monday.

The entire population of Fort McMurray, about 90,000 people, was forced to flee nearly two weeks ago as the uncontrolled wildfire raged through some neighborhoods and destroyed about 15 percent of structures.

On Monday, the blaze continued to burn uncontrolled, covering 285,000 hectares (704,000 acres), officials said. By Monday evening it was moving 30 to 40 meters (98 to 131 feet) per minute and had jumped a critical firebreak north of the city to push into the oil sand camp areas.

Roughly a million barrels per day of oil sands crude production was shut down as a precaution and because of disruptions to regional pipelines. Much of that production remains offline.

Firefighters have managed to protect much of Fort McMurray but evacuated residents have not been allowed to return to their homes, partly because of hot spots around the community.

(Reporting by Jeffrey Hodgson in Toronto; Additional reporting by Nia Williams in Calgary and Julie Gordon in Vancouver; Editing by Jeffrey Benkoe)