One location covered by the measure is the banks of the Canal Saint-Martin, among the city's most popular outdoor spots for lunch or an aperitif with friends.
“In the morning when there is nobody on the canal, I think it is a bit of a drastic measure," lawyer Helene Rames said after the face mask rule took effect.
Wearing a face mask outdoors also is required at the city's open-air markets, at popular tourist sites like Notre Dame Cathedral and Montmartre district neighborhoods, on several typically crowded streets and in parts of the Paris suburbs, authorities said.
A nationwide decree already requires people to wear masks in all stores and other indoor public places.
French health authorities warned Monday that the country is going backward in its battle against the pandemic.
After sharply curtailing the spread of the virus with a strict two-month lockdown, France has reported more than 10,000 new confirmed cases over the past week, and more than 300 virus clusters are currently active, according to figures released Monday by the national health agency.
France has stepped up testing in recent weeks, but the rise in infections is outpacing the rise in testing. Of all tests last week, 2.1% were positive, the highest rate since May. The number of patients in intensive care is also creeping upward, but at 396 is still far from the highs of more than 7,000 at the height of France's crisis in April.
France has reported over 30,300 virus-related deaths since the start of the pandemic, among the highest numbers in the world.
The health agency warned Monday that “the circulation of the virus is intensifying, notably among young people and in certain regions and the cities of Paris and Marseille.” It urged people to respect health safety measures so that “we can benefit from our vacations while protecting ourselves and others and especially the most fragile among us.”
Oleg Cetinic and Angela Charlton in Paris contributed.
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