Oil sands firms in Canada’s Alberta province are slowly restarting production after a massive wildfire forced a week-long shut down.
Shell Canada and Suncor said they had resumed oil production but at a limited rate.
Though most of the oil plants were not threatened by the fire, many oil workers were forced to flee as the city of Fort McMurray was evacuated.
Wildfires continue to devastate swathes of Canadian forest.
Fires are growing in Manitoba province, to the east of Alberta, on the border with Ontario.
The neighbouring US state of Minnesota has sent its firefighting planes to help the Manitoba authorities protect homes and a railway line in the Caddy Lake area.
Meanwhile, the New York Times reports scientists as warning for years of the threat to the huge boreal forest which encircles the Northern Hemisphere in a band near and just below the Arctic Circle, through Alaska, Canada, Scandinavia and Russia.
They say rising temperatures, drying trees and earlier melting of snow have contributed to a growing number of wildfires, burning through what makes up nearly a third of the forest land on the planet.
The fire that devastated Fort McMurray is continuing to burn and has merged with another fire further east, growing to some 229,000 hectares (560,000 acres), but it is moving into areas with no communities.
Original source: BBC News