Wearing a face-mask in public has become mandatory across Paris and several surrounding areas, amid a surge in Covid-19 cases in France.
The move comes a day after the country recorded 6,111 new infections – its highest number since early May.
The number of “red zones” where the virus is in active circulation has risen from two to 21.
Announcing new local curbs on Thursday, PM Jean Castex said he wanted to avoid another general lockdown.
He said the coronavirus was “gaining ground” across France, and that if the government did not act fast infection growth could become “exponential”.
Despite a sharp rise in cases in recent weeks, daily death tolls have remained low. Overall, more than 30,500 people have died and almost 300,000 have been infected in France.
A number of European countries are seeing a surge in new cases, and Germany is also planning tighter rules.
Masks for Paris
The prime minister said all pedestrians would have to wear face masks in public areas in the capital from 08:00 on Friday (06:00 GMT).
While individual streets and areas of the capital already have rules on wearing face-coverings, this new rule will be far more extensive, covering not only Paris but its inner ring of Seine-Saint-Denis, Hauts-de-Seine and Val-de-Marne.
On Friday the Paris police department clarified that people cycling or exercising outdoors would not have to cover their faces.
Paris is already a red zone, along with the southern area of Bouches-du-Rhône, where France’s second-largest city Marseille made masks compulsory from Wednesday evening.
A broad expanse of the Mediterranean coast and the Gironde area around Bordeaux are also red zones.