A Canadian court has ordered three tobacco companies to pay C$15.5bn (£8bn; $12bn) - the largest award for damages in the country's history.

The plaintiffs were Quebec smokers who said the firms failed to warn them of health risks associated with smoking.

Imperial Tobacco, Rothmans Benson & Hedges and JTI-MacDonald vowed to appeal against the decision.

The class-action lawsuits were filed in 1998, but only recently went to trial in the courts.

The firms argued that Canadians have had a "high awareness" of smoking health risks since the 1950s.

"That awareness has been reinforced by the health warnings printed on every legal cigarette package for more than 40 years," JTI-Macdonald said in a statement.

But the plaintiffs argued that the companies did not properly warn their customers and failed in their general duty "not to cause injury to another person", according to the Quebec Superior Court decision.

They represent nearly one million smokers who were unable to quit or who suffer from throat or lung cancer, or emphysema.