Four miners were killed and nine others missing in a coal mine gas outburst early Tuesday in east China's Jiangxi Province, local authorities said. The accident occurred at 5:28 a.m. Tuesday when 13 miners were working underground in a shaft of Xingfeng Coal Mine in Jianshan County, Gao'an City, Xinhua quoted the city government's information office as saying. Rescue operation is underway.