OTTAWA (AFP) - Canada said on Friday new rail cars used to transport fuel would be reinforced in order to avoid a repeat of the devastating explosion in Quebec last year that left 47 people dead.

Large swathes of the picturesque town of Lac-Megantic were reduced to rubble after a runaway freight train carrying fuel crashed and derailed in July last year.

The structural integrity of the DOT 111 tank cars involved in the accident came under scrutiny following the accident, after it emerged the United States (US) Department of Transportation had identified safety flaws in the early 1990s.

Canadian Minister of Transport Lisa Raitt said from now on DOT 111 tank cars would be required to be designed to meet stringent new safety regulations.

"It will require that new DOT 111 tank cars be built with thicker steel requirements, as well as adding top fitting and head shield protection to the tank car," Ms Raitt said in a statement.

"DOT 111 tank cars are used for transporting dangerous goods of high and medium danger, such as crude oil. Industry is already building new tank cars to this standard."

The new rules come into effect on Saturday.

Discussions with the oil industry were ongoing over the question of whether older DOT 111s which did not comply with the new standards would continue to be used.

The statement cames three days after a fresh derailment and fire involving 18 tanker wagons in the town of Plaster Rock, New Brunswick.

Last month, Ms Raitt said the government would reclassify crude oil as a highly hazardous material, upgrading its classification from flammable and non-explosive.

US transport officials last week indicated that oil shale extract from the Bakken Basin region in the northern US was probably more flammable than traditional crude oil.

The rail transportation of crude oil has increased dramatically in North America in recent years, driven by the boom in production of oil from unconventional methods such as fracking or hydraulic fracturing.