A gas explosion tore through a central Chinese coal mine on Sunday, trapping at least 188 miners and sending smoke billowing out the mine's air vents, the government said. The accident occurred in the state-owned Chenjiashan coal mine in Shaanxi province at 7:20 a.m. The Web site of the People's Daily, the mouthpiece of the ruling Communist Party, said 273 miners were underground when the blast occurred. By 10 a.m., 85 had been rescued, the site said. Staff at Chenjiashan said communications had been cut off with the trapped miners, the report said. A man who answered the telephone at the government office of Yao County, where the mine is located, confirmed that there had been an accident but refused to provide any more details. He said the accident was being investigated. During its noon newscast, state television said the explosion caused "big casualties" but did not elaborate. China's mines are the world's most dangerous, with thousands of deaths reported every year due to explosions, fires, cave-ins and flooding often blamed on lax safety rules and lack of required equipment. Last month, a massive explosion in the Daping Mine in central Henan province left 148 people dead. It was sparked after mine operators failed to realize that extending the mine's shaft would greatly increase its gas level.