Images of Muslim travellers in collective prayer at a French airport have caused controversy, with the government on Monday vowing 'firmness' and the airport operator describing the incident as regrettable.
The pictures shared on Sunday through social media showed several dozen travellers in the departures hall of Charles de Gaulle airport in Paris kneeling on the floor and praying together ahead of a flight to Jordan.
The incident comes as tensions rise in France over the war between Palestinian militant group Hamas and Israel.
France is home to large Muslim and Jewish communities.
Transport Minister Clement Beaune wrote on social media that airport authorities were fully committed to implementing rules and vowed "firmness".
The prayer at terminal 2B of France's largest airport, in which around 30 travellers took part, lasted around 10 minutes, an airport source who asked not to be named told French agency AFP.
Special closed areas are set aside at the airport for people of all faiths to pray in private.
France is strictly secular and there are limits on displays of religious belief in public spaces such as schools and public buildings including airports.
"This is a regrettable first," the chief executive of operator Aeroports de Paris (ADP), Augustin de Romanet, wrote on social media.
"Dedicated places of worship exist," he added.
"The border police have been instructed to prohibit this and will increase their vigilance."
De Romanet also warned against exaggerating the incident "at this time", in an apparent allusion to the war between Israel and Hamas.
The picture was notably shared on social media by Noelle Lenoir, a former European affairs minister under right-wing president Jacques Chirac.
"What does the CEO of Aeroports de Paris do when his airport is transformed into a mosque? Is the change in status official?" she asked sarcastically.
"There are specially dedicated places of worship at the airport," said ruling party MP Astrid Panosyan-Bouvet, adding that the authorities had to implement "the rules that prevail in France, including at the airports".
However Luc Carvounas, the Socialist mayor of Alfortville outside Paris accused Panosyan-Bouvet of "clumsy comments that could be compared to Islamophobia" and called on her to "clarify her remarks or even apologise".