If you are looking to fill the tank, Petro-Canada gas stations in Winnipeg are running dry.

Gas shortages that began last week at Petro-Canada outlets in Alberta, Saskatchewan, Manitoba and B.C. are now spreading to Winnipeg and northwestern Ontario.

The fires in Fort McMurray and an unplanned outage at an Edmonton refinery have contributed to the shortage, said a news release from Petro-Canada. Those factors have had "an unavoidable impact on our ability to produce and supply" the normal volume of gasoline and diesel, the release said.

On Monday, the company confirmed the outage continued and said it had "a team of people dedicated to this situation." It apologized to customers for the inconvenience.

At the Grant Avenue and Nathaniel Street location in Winnipeg on Monday morning, the cost of gas simply read 00.0 to signal to customers the lack of supply.

Dan McTeague, a senior petroleum analyst with Gasbuddy.com, said the gas shortage could last weeks. Shell Canada has also announced a maintenance issue at one of its refineries that could compound the problem, McTeague said.

"All of it suggests there is a very serious problem and the timing, of course, couldn't be worse given demand is very high at this time," he said.

"We're really living in an environment of absolute scarcity."

Canadians are currently paying about four cents more for gas because of the Petro-Canada shortage, he said.

"There's just no available barrels of gasoline.… There really aren't many available sellers right now," said McTeague.

The Petro-Canada gas station at Grant Avenue and Nathaniel Street in Winnipeg in out of fuel. (Travis Golby/CBC)

Petro-Canada officials said the company is bringing in additional supply for the Edmonton refinery and transferring in gasoline from other parts of the network by truck and rail. The company is also restarting oilsands operations and working to bring the affected unit back into service.

"We have a plan in place that will maintain supply at critical locations so as to minimize the impact on customers as much as possible," Petro-Canada said in a release.

"This includes supporting the community of Fort McMurray returning to their home, and adequately maintaining supply in areas where there are limited or no other options for fuelling."

Petro-Canada's parent company is Suncor.