BEIJING — A magnitude-6.3 earthquake hit the ​northwestern Chinese province of Qinghai ‌on Tuesday, killing at least one person and injuring four others, state media ​reported, citing emergency authorities. The quake ​struck a high-altitude area in the ⁠prefecture of Haixi in Qinghai ​with a depth of ten kilometers ​at 5:06 p.m. Beijing time (0906 GMT) on Tuesday, the China Earthquake Networks Center said. State ​media said all workers at ​coal mines near the epicenter have been ‌evacuated, and