Thirteen people were killed in two coal mine accidents in China at the weekend, state media said Monday -- the latest fatal incidents to strike the nation's notoriously dangerous collieries.

In the central province of Hunan, seven people were killed and one injured late Sunday in a gas accident at a mine in Lengshuijiang city, the official Xinhua news agency reported.

Earlier Sunday, six people were killed and 27 hurt in a similar incident in the southwestern province of Sichuan. Nearly 200 people were working at the mine in Rongxian county at the time, but most were able to escape.

Police have launched investigations into both accidents, Xinhua said.

Last year, 2,433 people died in coal mine accidents in China, according to official statistics, or a rate of more than six workers per day.

Labour rights groups, however, say the actual death toll is likely much higher than official data indicate, partly due to under-reporting of accidents as mine bosses seek to limit their economic losses and avoid punishment.