A gas explosion at a coal mine in China’s northern province of Shanxi killed at least eight people and trapped 38 underground, state media reported Saturday.The accident at Changzhi city’s Liushenyu coal mine happened on Friday evening, according to official news agency Xinhua, which reported around 247 workers were underground at the time. As of early Saturday, 201 had been brought safely to the surface.The cause of the explosion was under investigation, Xinhua reported.Chinese President Xi Jinping has called for an all-out effort to rescue the missing and an investigation of the accident’s cause while holding those responsible accountable, according to Xinhua.Shanxi province is known as China’s main coal mining province. With a size larger than Greece and a population of around 34 million, the province’s hundreds of thousands of miners dug 1.3 billion tons (1.17 billion metric tons) of coal last year, or almost a third of China’s total.