Authorities in Canada lifted evacuation orders on May 23 for all work camps and some additional oil facilities that had been shuttered when a massive wildfire threatened the nation's energy hub, a significant step for companies eager to restart production.

Municipal authorities for the oil town said a "phased re-entry" was authorized for the remaining camps, including those for Suncor Energy Inc.'s (NYSE: SU) Baseline and MacKay River camps north of the fire-ravaged oil town of Fort McMurray. There were no remaining camps under evacuation order in Alberta.

"The phased re-entry for all oil sands camps in the Regional Municipality of Wood Buffalo is now under way," said Robin Smith, a spokesman for the municipality. "They are cleared to return to operations as soon as possible."

South of the city, sites belonging to Athabasca Oil Corp. and Japan Canada Oil Sands Ltd. (JACOS) were slated for re-entry, authorities said in a statement, though they did not make clear which ones.

Both Athabasca and JACOS operate sites in the Hangingstone area southwest of Fort McMurray. The oil companies did not immediately respond to requests for comment.

The facilities were shuttered early last week as the huge wildfire surged toward the area around Fort McMurray, prolonging a shutdown that has cut Canadian oil output by a million barrels a day.

Fort McMurray itself still sits largely empty after its entire population of nearly 90,000 was evacuated when the fire hit earlier this month.

The lifting of evacuation orders means that workers can return to lodging sites as soon as the facilities are deemed safe by provincial forestry and health authorities, a process likely to be completed in the coming days, said municipality spokesman Smith.

By May 23, the inferno had charred more than 500,000 hectares (1,930 square miles) across northern Alberta, though its footprint remained unchanged since Friday and it was not expected to grow due to damp, cold weather, wildfire information office Laura Stewart said.

News of additional camps set to re-open came a day after authorities announced a similar plan for camps near Nexen Inc.'s (NYSE: NXY) Long Lake and ConocoPhillips's (NYSE: COP) Surmont facilities, both of which had stopped production due to the fire.

Camps were also due to re-open near Enbridge Inc.'s (NYSE: ENB) Cheecham terminal, which the company has said was returning to full service.

An Enbridge spokesman said the company's Cheecham terminal and its pipelines were operational, and they would be ready to ship oil as producers "come back online." He declined to comment on the facility's current volume.

ConocoPhillips said it started a staged re-mobilization plan at Surmont, and by Friday expected to have 350 people back on site, though there was no immediate indication of its schedule for restarting production, a spokesman said on May 23.

Cogeneration electric plants' output around Fort McMurray edged up to 477 megawatts (MW) by early May 23 from 455 MW the afternoon of May 20, according to the Alberta Electric System Operator (AESO).