Around 12,000 people have been urged to leave Canada's oil sands camps near the fire-hit town of Fort McMurray as a resurgent wildfire heads towards them.
A regional official told the BBC that 8,000 people were given precautionary evacuation orders late on Monday, in addition to some 4,000 who had already been advised to leave.
More than 80,000 people fled the fire that hit Fort McMurray two weeks ago.
Air quality in the Alberta city is still at dangerously high levels.
A reading on Monday found the level to be 38 - far exceeding the provincial index's most dangerous level of 10.
The vast fire had moved away from Fort McMurray but in recent days it has started to threaten the area again.