TORONTO — A Canadian National Railway Co. train carrying crude oil that derailed near the northern Ontario community of Gogama early on Saturday was still on fire late on Sunday, the company said.

The derailment is CN’s second in the region in just three days and third in less than a month. It was the latest in a series of North American derailments involving trains hauling crude oil, raising concerns about rail safety.

“Fire suppression activities are beginning, as is construction of the track diversion,” CN spokesman Mark Hallman said in an email, adding that responders were working in shifts around the clock.

He said air quality monitoring has indicated no air issues at either Gogama or a nearby aboriginal community.

The Ontario Provincial Police said at midday on Twitter that the fire was burning at 80 percent of full size and posted a photo from the morning showing thick clouds of black smoke still coming from the site.

The police force reopened a nearby highway closed after the derailment, but warned there would be delays for residents as CN moves equipment.

The railway said on Saturday that a bridge over a waterway had been damaged and that five tank cars had landed in the water. Oil had leaked into the water and booms were deployed to try to contain it.

CN said the crude oil on the train originated in Alberta and was destined for Eastern Canada.

The incident comes after another derailment, on Thursday, blocked CN’s main line in northern Ontario.

CN said the latest derailment occurred 2 miles northwest of Gogama, which is some 373 miles north of Toronto. It occurred just before 3 a.m. on Saturday and is affecting rail traffic running between Toronto and Winnipeg, Manitoba.

The Transportation Safety Board of Canada, which is investigating, noted on Saturday that the accident occurred about 23 miles from the site of a Feb. 14 accident involving a CN crude oil train.