Explosion reported at Irving Oil's St John refinery, the largest in Canada

Aaron McKenzie Fraser | Bloomberg | Getty Images

The refinery of Irving Oil Ltd. is on this aerial photograph taken over Saint John, New Brunswick, Canada, on Tuesday, August 5, 2014. Irving Oil Ltd.

Irving Oil confirmed a "major incident" at Canada's largest refinery after residents in the area reported an explosion at the facility, a key source of fuel for the Northeastern US market.

@irvingoil: We can confirm that a major incident occurred at our Saint John refinery this morning. We are actively evaluating the situation at this time and will share more information when it becomes available.

The plant has the ability to refine 320,000 barrels a day of gasoline, diesel fuel oil, jet fuel and other petroleum products. Irving Oil exports more than half of this supply to the United States.

Photos from Saint John's Irving Refinery published on social media showed flames and black clouds against a blue sky. Residents reported that an explosion had rocked the houses.

The refinery employs 1,400 workers and is located on a 780-acre lot in an area with "thousands" of neighbors, according to the Irving Oil website.

@bmaguirens: My friend Jill just published these photos from the St John & s Refinery in New Brunswick. I hope everyone is fine. An explosion shook his house.

Futures prices for crude oil and gasoline rose after reports.

The refinery is probably the largest in terms of fuel imports into the North American market, according to Tom Kloza, global leader of energy analysis at the Oil Price Information Service.

"We are probably importing more gasoline from this refinery than any other refinery in the world," he said.

@DavidKellyNB: #Saintjohn emergency at the refinery. #NB

Irving Oil did not immediately return requests for comments.