LAC MEGANTIC, Canada / Quebec — A freight train loaded with oil derailed in Canada's Quebec province Saturday, sparking thunderous explosions that engulfed about 30 buildings in fire, killed at least one person and reportedly left dozens missing.

The accident created a spectacular fireball, witnesses said, and forced 2,000 people from their homes.

The flames were still not under control hours later in Lac-Megantic, around 250 kilometers (155 miles) east of Montreal, near the US border and state of Maine.

Witnesses reported as many as six major explosions during the night. Michel Brunet, a spokesman for Quebec's provincial police said at least one person was killed and a second was injured in the incident.

But Radio-Canada reported some 60 people were unaccounted for in Lac-Megantic, a picturesque resort town of 6,000 residents.

"There have been several reports" from people who said they were unable to reach relatives who lived near the accident site, Brunet said.

"The fire is still raging, our investigators have not yet even be able to get close to the scene," Brunet added, more than 12 hours after the train went off the rails at around 1:20 am (0520 GMT).

An initial evacuation zone of a kilometer around the crash site was widened Saturday afternoon as a precaution against harmful particles in the air, bringing the total to 2,000 people forced to leave their homes.

Some 150 firefighters were battling the blaze, including some who came across the border from Maine, just 25 kilometers south of the town.

"No conductor on board"

The cause of the crash was still unknown, but a spokesman for the company told AFP the train had been stopped in the neighboring town of Nantes, around 13 kilometers west of Lac-Megantic, for a personnel changeover.

For an unknown reason, he said, the train "started to advance, to move down the slope leading to Lac-Megantic," even though the brakes were engaged.

As a result, "there was no conductor on board" when the train crashed, he said.

An investigator from Canada's transportation safety agency was quickly dispatched to the scene to investigate.

One witness, Nancy Cameron, posted a photo on social media websites showing one of the train's locomotives spouting flames near Nantes.

Others were in Lac-Megantic when the train came barreling in.

"When we came out of a bar, we saw cars arriving in the center of town at full speed," another witness, Yvon Rosa, told Radio-Canada.

"We heard explosions and there was fire everywhere. We ran to the edge of the water," Rosa said.

Prime Minister Stephen Harper offered his "thoughts and prayers" to the community, adding "the people of Lac-Megantic and surrounding areas can rest assured that our Government is monitoring the situation and we stand by ready to provide any assistance requested by the province."

The Montreal Maine & Atlantic train consisted of five locomotives and 77 rail cars and was carrying oil from the US state of North Dakota, the company's vice president of marketing, Joe McGonigle said.

But Quebec authorities spoke of 72 cars transporting 100 tonnes of oil each. "Around 10 cars have been secured and separated from the train," the Quebec emergency agency said in a statement.

The Montreal Maine & Atlantic company has a network of more than 800 kilometers through Quebec and New Brunswick provinces and the neighboring US states of Maine and Vermont.

Copyright © 2013 AFP. All rights reserved.