Paris is said to be suffering its worst winter pollution for at least a decade, with the French capital clouded by thick smog and gripped by travel chaos, according to Sky News.
Airparif agency, which measures pollution in the city, said it was also experiencing its most prolonged period of pollution for 10 years.
The city authorities imposed driving restrictions on Wednesday. Only vehicles with an odd number registration plate, electric or hybrid vehicles, and vehicles with more than three people on board are allowed on the roads.
Public transport in Paris is free for a second day to try to ease the disruption.
The smog is caused by emissions from vehicles, as well as domestic wood fires, and Airparif said near windless conditions meant pollutants had not been dispersed.
Londoners were also warned this week that the pollution in France could affect the capital.
Experts at King’s College London said air flowing into the city was forecast to have travelled up through France and close to Paris.
City Hall put out air pollution alerts for Westminster and the City, as well as other busy roads.