Face masks became mandatory in tourist hotspots in Paris on Monday as French authorities imposed new measures to curb a rise in coronavirus infections.

The order covers busy outdoor areas in the French capital including the banks of the River Seine and the iconic Montmartre area in Paris’s far north – although other renowned tourist hotspots such as the Eiffel Tower, the Arc de Triomphe and Champs-Élyseés were not listed. Anybody aged 11 faces a €135 ($159) fine if caught without a mask where one is required.

The requirement came as France along with much of Western Europe swelters in a heatwave, with temperatures soaring above 35 degrees Celsius (95 F).

France is one of several European countries to have seen a spike in new Covid-19 infections over recent weeks, prompting fears of a second wave. It reported 2,288 new infections last Friday, a new post-lockdown high, with the seven-day moving average at 1,486, a level unseen since late April.

People have been required to wear face masks in all enclosed public spaces in France since July 21.

The latest uptick in Covid-19 cases has been most marked in Paris but some other cities including Nice, Toulouse, Biarritz, Marseille and Lille have already ordered people to wear masks in busy outdoor areas. Several coastal towns popular with tourists – including Le Touquet in the Calais region, Saint-Malo on Brittany’s northern coast, and La Rochelle on the Atlantic coast – have done the same.

Yet for some tourists braving the heat on the streets of Paris, the rules listing specific zones are not clear enough.

“We’re tourists so we don’t know in which zones we’re required to wear a mask,” Dominico Ditoma, a French tourist visiting Montmartre with his family, told Reuters. “We assume it’s for tourist spots but there are no signs so it's quite unclear.”

A foreign tourist who gave her name as Angelica was also uncertain, telling Reuters: “I’ve heard about it, it starts this morning, but I don’t know about the zones, I don’t know how to get informed.”

Paris council official Audrey Pulvar defended the complex mask map – which is available on the city’s website – saying that it was “evolving” and based on criteria such as people’s ability in a given space to comply with social-distancing rules.

“That’s why, in certain streets, parts are affected by the measure and parts are not,” Pulvar told French media network BFM TV. (France 24 with AFP and Reuters)