BEIJING : Beijing began massive nucleic acid tests on more than 100,000 students, faculty and staff from nearly 100 universities as part of the city's effort to curb the latest outbreak of the coronavirus which has so far led to 311 local cases.The mass testing brought the number of Beijing residents who had been checked to more than 7 million, city authorities said on Sunday, since a cluster of cases emerged in early June linked to the Chinese capital's sprawling Xinfadi wholesale food market, South China Morning Post reported.Tests have been carried out on people living close to markets, as well as those who work in the public domain, including banks, transport, dining facilities, beauty parlours, delivery services and community.