At least 21 people were killed and a dozen others hurt Tuesday when a bus and coal truck collided in China's northwest Xinjiang region, a state-run news agency reported. The head-on collision happened on a highway in a remote area, the Xinhua News Agency said. Two vehicles were damaged and three of the 12 injured were in serious condition, Xinhua said. The report did not provide other details. Road accidents are common in China because of overloaded and unsafe vehicles, poor road conditions and bad driving habits.