In China, at least 20 coal mine workers have been killed after a gas explosion hit a colliery in central China's Henan Province. Another 17 miners are still believed to be trapped underground.The State Administration of Work Safety in a statement said altogether 276 workers were in the mine at the time of the accident and 239 of them safely resurfaced.The accident occurred this morning in a pit in Yuzhou City. Rescue operations are underway.