BEIJING - The toll from an accident in which a bus fell into a ravine in central China's Henan province rose to 15 dead and five critically injured, the state-run Xinhua news agency said on Saturday.

The bus, which veered off a mountain road and plunged into the ravine in Mianchi county on Friday, was carrying 35 passengers, Xinhua quoted government sources as saying. Officials are investigating the cause of the accident, it added.

Of the 20 people injured, five were in critical condition, seven seriously injured and the rest stable, Xinhua said.