George Russell in Hong Kong
The Swiss executive body, the Federal Council, introduced new restrictions on Sunday to counteract the so-called "rapid increase in coronavirus infections".
As of Monday, gatherings of more than 15 people will be prohibited, while the wearing of masks in "indoor public areas", including at all train stations, airports, and bus and tram stops, is mandatory.
The mask mandate also applies to stores, shopping malls, hotels, banks, post offices, museums, libraries, cinemas and other venues.
Switzerland has discovered an average of 1,771 new daily cases in the past week and is one of the few countries to have more than 1,000 daily cases.
In an English-language statement on its website, the Federal Council recommended that employees work from home.
According to the Federal Office of Public Health, 74,422 people in Switzerland and Liechtenstein have tested positive for coronavirus and 1,823 have died since the epidemic began.
Restaurants, bars and clubs remain open, but food and drinks can only be consumed while seated.
"There will be closings," said Alexander Bücheli from the Zurich Lawyers and Club Commission, an industry group, on Sunday opposite the Neue Zürcher Zeitung.