BEIJING — China's National Health Commission on Aug 13 issued an updated version of its guidelines on regular epidemic prevention for key areas, sites and population groups.

According to the new version of the guidelines, COVID-19 prevention measures are tightened for certain places, including border ports, chess rooms, sightseeing boats, theaters, gyms and educational institutions.

Regarding chess rooms, which are confined spaces with a large crowd, people must take body-temperature tests and have their health codes checked before entering. Masks are also required in chess rooms.

The guidelines also step up the requirements for key groups, especially for airport workers and crew members on international flights.