(CNN) -- An underground explosion in a coal mine in central China's Henan province killed at least 46 miners early Monday, state media reported.

The Xinhua news agency said 26 of the 72 miners trapped by the explosion were able to escape.

Officials are investigating what caused the blast, which apparently occurred in the explosives storage area of the mine around 1:40 a.m. (1:40 p.m. ET), Xinhua said.

The mine, located in Pingdingshan City, has an annual production capacity of 90,000 metric tons of coal, according to Xinhua.

Mine accidents are common in China.

On May 30, a coal mine blast killed 17 miners in Hunan province. On May 13, a coal mine explosion in southwestern Guizhou province killed 21 workers. And in April, the Wangjialing mine in Shaxi province flooded, leaving 153 workers trapped. Rescue workers pulled out 115 alive.

In 2009, 2,631 people were killed in mine accidents in the country. The figure, while high, is down from 2002 when 6,995 people died.

In April, China launched a two-month campaign to review safety regulations in mines and other industries that have had serious accidents.