The death toll in a coal mine accident in eastern China rose to 12 on Friday, state media reported, after rescuers found the body of the last missing miner. The miners were working in the colliery in Jiangxi province on Tuesday when it was hit by a "coal and gas eruption", Xinhua news agency said, without elaborating. Police have detained the private mine's owner and were investigating the cause of the accident, the report said. Deadly accidents are rife in China's coal sector, where safety concerns are widely ignored in the rush to satisfy surging demand for the fuel -- source of about 70 percent of the country's energy. More than 2,600 miners were killed in China last year, according to government figures, although labour activists say the actual numbers are probably far higher.