Some French local authorities are being forced to revise orders making mouth and nose coverings compulsory as courts side with civil liberties groups.

A court in Lyon ruled on Friday that making face masks mandatory in all public spaces in Lyon and neighboring Villeurbanne constituted a "serious and illegal infringement" of citizens' liberties.

It added that health authorities have "only recommended wearing of masks in cases of gatherings with a high density of people outside" and gave the prefecture until September 8 to amend their orders to exclude areas where conditions were not "likely to favor the spread" of the disease.

Officials must also remove periods of the day in which "there is no particular risk of spreading the virus" from the orders.

A civil liberty group called "Les Essentialistes" brought the case against authorities arguing that the decrees were disproportionate and inefficient.

The prefecture said on Twitter that "took note" of the ruling and that the judge had "confirmed the validity" of setting up a rule enforcing mandatory mask-wearing.

The ruling in Lyon followed two similar decisions earlier this week in Strasbourg, in the north-east of France, and Seine-Maritime, in the north-west.

Seine-Maritime, which includes the cities of Rouen and Le Havre, saw a judge rule that obligatory mouth and nose covering should be limited to the most densely populated areas between 07:00 and 02:00 and not be applied in natural spaces or when performing physical activity.

The prefecture issued a new decree on Friday which now only affects 44 municipalities, down from 71 previously.

"In the Seine-Maritime department, the virus is still actively circulating," the prefecture said in a statement.

"In Normandy, the effective reproduction rate of the virus, which corresponds to the number of people that a positive case will infect, is now 1.51 as of August 28, 2020.

"The departmental incidence rate, i.e. the number of positive cases per 100,000 inhabitants, has reached 17.19, which is above the vigilance threshold of 10," it added.

In Strasbourg, situated in the Grand-Est region, which is among the most heavily-impacted in the country, a judge also ordered that municipalities with low population density be excluded from the rules making masks mandatory.

The association "Victims of COVID-19 France" has announced it plans to take similar legal action in at least 15 other cities across the country.

"We are neither for nor against the mask, but the right mask, at the right time, in the right place, we are for coherence and proportionality of actions about the situation.

"We ask for the for the obligation to wear masks outside to be suspended," the group said on Twitter.

The government has made face masks mandatory on public transport and at work to curb the spread of SARS-CoV-2 — the virus that causes COVID-19 — but several cities in France including Paris, Toulouse and Marseille have also made them compulsory outside.

The country is among the hardest-hit in Europe and has so far recorded more than 300,000 confirmed cases and 30,706 deaths.