BEIJING (AP) — Police in central China's Hunan province have arrested a coal mine manager on suspicion of under-reporting the death toll from an explosion this week.

The official Xinhua News Agency reported Saturday that the official death toll climbed to 10 after investigators found a miner who had been listed as "injured" in the Tuesday blast. The agency said that police detained a manager surnamed Liu on suspicion of covering up the death.

Authorities at the "high gas" Zubao Coal Mine initially said that nine out of 29 people working in the pit had died. Gas explosions inside mines are often caused when a flame or electrical spark ignites gas leaking from the coal seam.

Three local government officials including two deputy mayors are also under investigation.

Mines in China, the world's largest consumer and producer of coal, are notoriously unsafe despite government pledges to improve work safety standards and shut down outdated facilities. More than 500 workers died in mining accidents in 2016, according to government statistics.