Police have detained the duty manager at an illegal coal mine in southwest China after he staged a fake escape from an accident that killed 34 workers, an official said Monday. Qi Guming smudged coal dust on his face and told investigators he had used a tunnel to escape from the pit, where another nine workers remain trapped four days after the accident, a local official told AFP. According to China National Radio, Qi was actually asleep and not inside the mine when a blast of coal and gas took place early Thursday morning in the mine in China's Yunnan province. He was supposed to be the duty manager for the night shift. "Qi Guming wasn't in the mine when the accident happened," a spokeswoman for the city of Qujing, where the mine is located, told AFP by phone. "Afterward, he made his face dirty and lied to the rescue group. The police have made this clear," added the official, surnamed Zhou. Coal mine accidents are common in China, where work safety is often neglected by bosses seeking a quick profit. To try to minimise accidents, authorities ruled recently that at least one manager must be in the pit when work is going on. The Yunnan mine was hit Thursday by what authorities called a coal and gas outburst -- a sudden and violent ejection of coal, gas and rock from a coal face -- trapping 43 workers underground. Authorities said the gas leak had hampered rescue operations at the mine. "Nine remain missing and there is only a slim chance we will find them alive," an official at the Yunnan Administration of Work Safety told AFP by telephone Monday, without giving his name. Last year, 2,433 people died in coal mining accidents in the country, according to official statistics -- a rate of more than six workers per day -- but labour rights groups say the true figure may be much higher. The accident in Yunnan came days after a rock blast in a coal mine in the central province of Henan trapped dozens of workers underground, many of whom were later rescued, although 10 were killed. Last month, a gas explosion at a state-owned coal mine in neighbouring Hunan province left 29 miners dead.