More than 50 people have been killed in a blast at a coal mine in the central Chinese province of Shanxi that trapped dozens more.State news agency Xinhua reported that the gas explosion happened in Qinyuan county, about 520km (320 miles) southwest of Beijing, on Friday after the mine issued a carbon monoxide alert late on Friday.There were 247 workers underground at the time of the blast. It was unclear whether other workers remained trapped.President Xi Jinping called for rescuers to “make...