Forest fires in northern Alberta have forced crews cleaning up the province’s largest oil spill in decades to evacuate.

The Northern Sunrise County Emergency Response Centre issued an evacuation order effective 11:00 a.m. Sunday morning for the area affected by Plains Midstream Canada’s Rainbow pipeline leak, according to a release.

"Clean-up operations will resume once the evacuation order is lifted, and it is determined safe to do so," the company said in a release. "The safety of our workers remains our primary concern."

Approximately 4.5 million litres of crude poured out of the pipeline April 29.

According to Alberta Sustainable Resource Development, 67 new wildfires have been sparked to date in the province over the weekend and 25 of those have been deemed "out of control."