BEIJING, March 24 (Xinhua) -- China still encourages healthy people to wear face masks as they have the risk of being infected by those carrying the novel coronavirus, but having not shown symptoms yet.

People should wear face masks in crowded places or when they need to get in close contact with crowds, said Wu Zunyou, a researcher with the Chinese Center for Disease Control and Prevention, at a press conference.

The public should stay alert in dangerous environments, including medical facilities where COVID-19 patients are treated, around families of these patients and closed venues like elevators and public transport, Wu said.

However, people do not have to wear face masks in open spaces as is advised in a guideline recently issued by the National Health Commission, Wu added.