TORONTO (Reuters) - One person was killed and a second was injured in an explosion at Nexen Energy’s Long Lake oil sands facility south of Fort McMurray, Alberta, on Friday, the company said.

The injured person was in critical condition, a police spokesman said. Other personnel were accounted for after the explosion, the unit of China’s CNOOC Ltd said in a statement.

“The affected facility has been shut down and we are stabilizing the scene. There is no immediate danger to the neighboring communities or personnel still on site,” the company said.

The early indication is that the explosion happened in the facility’s hydrocracker, said Staff Sgt Jeremie Landry, a spokesman for the Royal Canadian Mounted Police.

“There was an explosion as well as a fire,” he said.

According to the company’s website, the hydrocracker is where hydrogen is combined with partially upgraded oil to remove sulfur and produce synthetic crude.

The company said regulators had been notified. A company spokesman did not immediately respond to a request for additional details.

The incident comes after Nexen last July discovered a pipeline leak near the site that caused one of North America’s largest oil-related spills on land.

The Alberta Energy Regulator last August ordered Nexen to shut 95 pipelines at the Long Lake facility as part of an investigation into the spill. It resumed full production in September.

The Long Lake facility was producing about 50,000 barrels a day of synthetic crude before the July spill.