BEIJING

 Beijing on Wednesday closed around 10% of the stations in its vast subway system as an additional measure against the spread of coronavirus.

The subway authority in a brief message said only that the measure to shut 40 mostly downtown stations was being taken as part of epidemic control measures. No date for resumption of service was given.

Beijing has been on high alert for the spread of COVID-19, with restaurants and bars limited to takeout only, gyms closed and classes suspended indefinitely. Major tourist sites in the city, including the Forbidden City and the Beijing Zoo, have closed their indoor exhibition halls and are operating at only partial capacity.

A few communities where cases were discovered have been isolated. People residing in “controlled” areas have been told to stay within city limits, including 12 areas deemed high-risk and another 35 considered medium-risk.

City residents are required to undergo three tests throughout the week as authorities seek to detect and isolate cases without imposing the sort of sweeping lockdowns seen in Shanghai and elsewhere. A negative test result obtained within the previous 48 hours is required to gain entry to most public spaces.