BEIJING—A city in southern China that is trying to contain a COVID-19 outbreak told the public Sunday not to leave town, suspended bus and train service, and closed cinemas, bars, and other facilities. Anyone who needs to leave Putian, a city of 2.9 million people in Fujian province south of Shanghai, for an essential trip must have proof of a negative COVID-19 test within the past 48 hours, local authorities announced. The first cases in Putian were students from Xianyou county, according to the state-run Global Times newspaper. The traveler, identified by the surname Lin, underwent a 14-day quarantine and nine nucleic acid and serologic tests, all of which were negative, the Global Times said, citing local authorities. It said he tested positive on Friday. Residents of villages in Xianyou where infections were found were barred from leaving, the newspaper said. Bus and train service to Putian was suspended Saturday, …