FORT MCMURRAY: A ferocious wildfire wreaking havoc in Canada could double in size Saturday, authorities warned, as a risky convoy operation to bring thousands to safety through the burning town of Fort McMurray entered a second day.

As the flames pursued their path of destruction, armies of firefighters sought to protect what was left of homes and other infrastructure in Alberta’s parched oil-sands region.

Monster fires were continuing to rage out of control and could potentially double in size by the end of Saturday, said Chad Morrison, senior manager of wildfire prevention at the Alberta Agriculture and Forestry Division.

But Morrison noted that winds were expected to push the fire away from populated areas into nearby forests.

The blaze will not be extinguished for “a very long time,” until there is significant rain, he said.

There was a 30-percent chance of rain on Sunday, Canadian government forecasters said, followed by sunny conditions on Monday. More rain was possible later in the week.

In the latest harrowing chapter, convoys of 50 cars at a time made their way through Fort McMurray at about 50-60 kilometers per hour (30-40 miles per hour) Friday, TV footage showed.

Police took up positions at intersections along the way to keep evacuees from detouring to try to salvage belongings from charred homes — 2,000 of which have been destroyed — and make sure the route remained safe. The fire has encircled the town of 100,000, now evacuated.

Three army helicopters hovered above to sound the alert if the flames got too close to the road, Highway 63, or cut it off completely, as has happened in recent days.

Those being evacuated — for a second time, after first abandoning their homes — had fled this week to an area north of the city where oil companies have lodging camps for workers.