France's two biggest cities, Paris and Marseille, have been declared high-risk Covid-19 areas – known as red zones – after health officials announced a sharp increase in nationwide infections.
The government decree grants authorities powers to impose local restrictions to contain the spread of the disease in high-risk areas.
France has seen a sharp increase in Covid-19 infections over the past two weeks. On Thursday, more than 2,600 new infections were reported for the second day in a row.
"Indicators used for tracking the epidemic on French territory have clearly worsened in recent days," the DGS public health division said on Wednesday.
At 2.2 percent, the weekly rate of positives was up from 1.6 percent the week before, confirming "increased viral circulation".
Virus targets younger victims
Of 600,000 tests over the past week more than 11,600 were positive.
The pace of growth in cases in the week of August 3-9 was fastest among people aged 15-44, the DGS said, calling it a "troubling situation".
There has been some concern in the rise of an anti-mask movement, particularly among young people, who feel they are not at risk from the virus and view the rules as an infringement on their freedom.
Earlier in the week, French Prime Minister Jean Castex insisted that Covid-19 could get out of hand if people do not take precautions, which included wearing a mask when in crowded outdoor areas.
The warning comes with France only halfway through the summer holiday month of August.
"It's imperative that we keep up our efforts to avoid the epidemic picking up again, individually and collectively, everywhere and at all times", the DGS said.
Based on Friday's decree, local authorities in Paris and the southern Bouches-du-Rhone area will now have powers to limit the circulation of people and vehicles, restrict access to public transport and air travel, limit access to public buildings and close restaurants, bars and other establishments.
Paris and Marseille had in recent days already made the wearing of face masks mandatory in busy public areas, following on from a host of other French cities.
Wearing masks in indoor public areas came into force on 20 July.
Anybody over the age of 11 faces a 135 euro fine for failure to respect the rule.
Tourism to take a hit
The spike in new infections in France is likely to have a negative impact on tourism, as countries respond by introducing travel restrictions from so-called "hotspots".
Britain on Thursday announced all travellers arriving from France and the Netherlands would once again be subject to quarantine. This follows restrictions placed on Belgium, Andorra and the Bahamas.
France responded with reciprocal measures.