Seven miners trapped since earlier this week in a flooded colliery in central China have been found dead, state media said Friday, citing rescue workers. Emergency personnel found the men's bodies at a depth of 90 metres (300 feet) in the Yide coal mine in Hunan province's Xiangtan city, where the flood occurred late Tuesday, the Xinhua news agency reported. Cave-ins and a lack of oxygen in the shaft has hindered rescue efforts, the report said. Police have detained senior mine executives and shareholders, Xinhua said, adding that the local work safety authority had warned mine managers in the month prior to the accident of potential safety hazards faced by the workers. The cause of the accident was still under investigation. China's notoriously dangerous coal-mining sector is regularly hit by deadly accidents blamed on the flouting of safety rules as operators try to keep costs down. The rescue in October of 33 Chilean miners after more than two months underground sparked criticism in China of the government's inability to prevent such mishaps or successfully rescue miners stricken by accidents. Last year 2,631 Chinese miners died in the line of work, according to official statistics, but independent labour groups say the true figure is likely to be much higher as many accidents are believed to be covered up. The government has repeatedly vowed to shut dangerous mines and strengthen safety but the accidents continue with regularity as mines rush to pump out the coal on which China relies for about 70 percent of its energy. In a rare moment of good news for the accident-prone industry, 29 miners were freed from a flooded coal mine in southwest China last month. 