When an imam gave "radical" sermons, they were said to "back jihad." A mosque in the northern French region of Oise has been shut down because of this.
Authorities in the town of Beauvais say that the mosque in the town will be closed for six months.
Oise's prefect said sermons there called jihadist fighters "heroes" and made people want to be angry and violent.
For the last few weeks, France has been doing checks on Islamic places of worship that are thought to be linked to extremism.
There is a big mosque near Paris called the Great Mosque of Beauvais, which is about 100 kilometres (62 miles) north of the city.
The imam there "targets Christians, homosexuals, and Jews" in his sermon. Gérald Darmanin, the interior minister, started a process two weeks ago to close the mosque.
The imam of the mosque was a recent convert to Islam, AFP said, citing a local newspaper.
A lawyer for the group that runs the mosque told the newspaper that his words had been "taken out of context."
He was said to be a "occasional speaker," but the interior ministry said he was actually a "imam." He had said that "a rigorous practise of Islam" and "its superiority to the laws of the Republic" were important.
Muslims are under pressure to sign a French charter of values.
France is split even more after the beheading of a teacher.
Last year, Mr. Darmanin said that some mosques with extremist links could be closed if they were found to be encouraging "separatism."
Because Samuel Paty was killed and three people were killed in a Nice cathedral in October 2020, Islamist extremists are to blame for both of these events.
There are more than 2,600 mosques and prayer halls in France. The interior ministry says it has looked into about 100 mosques and prayer halls in the last few months for extremism.