PARIS — An exodus from Paris at the Gare Montparnasse train station. A postal worker warning of the plague, the apocalypse and repentance, with the Eiffel Tower behind him. Fear in people’s eyes, and tense moments, in a long line outside a supermarket.

But also Parisians out jogging on deserted streets. Or walking their dogs, or trying to connect their children to their teachers on home laptops. And a California couple savoring, for now at least, their first trip to the City of Lights.

As France was put on lockdown on Tuesday to contain the spread of the coronavirus, Paris, one of the world’s most visited cities, turned into a ghost town. At noon sharp, police officers patrolling the Champs-Élysées, near the Arc de Triomphe, began enforcing new rules of confinement across the capital and the rest of France, one of the hardest-hit countries in Europe with 6,600 cases and 148 deaths.

In what has been described as the toughest health-related restrictions in France’s modern history, people will be allowed outdoors for only specific reasons for at least the next 15 days; the exceptions include buying groceries, getting medication at a drugstore, or commuting to work for those unable to work remotely. People leaving their homes now have to sign and carry a form explaining the reasons for their movements, or face fines. Across the city, police officers began stopping pedestrians and pulling over cars to inspect their papers.