CHANGCHUN, Jan. 16 (Xinhua) -- A city in northeast China's Jilin Province on Saturday reported 49 new asymptomatic infections of the novel coronavirus as of 10 a.m., authorities said.

The cases were all close contacts or secondary close contacts of earlier infections exposed in a local training course in the city of Tonghua, according to a press conference held by the city government Saturday.

Related epidemiological investigations are underway.

A total of 42 residential communities in connection with the cases have been closed off, and the close contacts and secondary close contacts of those infected have been quarantined.

As of 10 a.m. Saturday, 73,362 of some 209,000 residents who were tested for the virus in a citywide testing campaign have received their results, which are all negative.