Four miners have been killed and five others still trapped in a coal mine roof fall accident in north China's Shanxi Province, Xinhua quoted officials with the provincial work safety bureau as saying. The accident occurred at around 5:20 a.m. Friday at a mine in Jingle county of Xinzhou City when 16 people were working underground. Seven managed to escape safely. Rescue work is under way. Officials from the provincial work safety bureau and the Xinzhou municipal government have arrived at the mine. The mine is a licensed one and has an annual capacity of 150,000 tons. Authorities are investigating into the cause of the accident.