Gas explosions in two different regions of China have killed more than 50 coalminers, the Xinhua news agency reported on Sunday, the latest fatalities to hit the world's deadliest mining industry.
An explosion on Saturday in a privately owned mine in Fuyuan, in the southwestern province of Yunnan, killed 32 men and injured 28, local officials told the news agency.
Earlier that day, at least 21 died in a blast at the Yuanhua mine in Jixi, in the northeastern province of Heilongjiang.
Four miners managed to escape and rescuers were searching for six who were still missing, the reports said.
The Yuanhua mine is privately owned with an annual production capacity of 30,000 tons, Xinhua said.
It said the causes of the explosions were being investigated.
A total of 3,726 miners died in more than 2,300 floods, blasts and other accidents in the nation's coal mines in the first 10 months of 2006.
The cold statistics highlight China's struggle to clean up the industry while trying to meet booming demand and high prices for coal, which fuels about 70 percent of its energy consumption.
An official Communist Party report released this month noted that coal mining safety had worsened since the beginning of the winter heating season. It said the sharp increase in demand for coal often caused mine managers to breach safety laws.
Xinhua said on Friday that authorities had sacked two local government chiefs and their deputies after a series of coal mine accidents in the northern province of Shanxi in the past month that killed 55 people.