The shooting, which was not being treated as terrorism, took place in Avignon, Provence, at about 10.30pm on Sunday night.
Worshippers were leaving the Arrahma mosque when at least two “hooded men” pulled up in a Renault Clio.
Police said the crowd fled in panic when the gunmen, armed with a handgun and a shotgun, started shooting.
Four people were injured at the scene, La Provence newspaper reported, and a family of four in a nearby apartment received shrapnel wounds.
A seven-year-old girl was among those injured, the paper reported.
Police were searching for the suspects after they fled from the scene. Witness accounts mentioned four men in the car.
The prosecutor’s office ruled out terrorism.
“From what we know this evening, the mosque was not targeted. The fact that it happened in the street of the religious establishment was unconnected with it,” the prosecutor said.
The shooting comes two weeks after a man attacked worshippers outside a Finsbury Park mosque in London, killing one and injuring nine.
With France’s Muslim community already on edge after the London attack, a man tried to drive his car into worshippers a few days ago outside the Creteil mosque in south-east Paris.
The driver, a 43-year-old Armenian who suffered from schizophrenia, hit barriers and pillars outside the mosque with his 4×4 without causing any injuries before crashing into a traffic island.
According to a source close to the investigation, the suspect had made “confused remarks in relation” to a string of jihadist attacks that have struck France, killing 239 people since 2015.
Some Muslim officials have described the Paris incident as an attack and called on the authorities to “strengthen protection of places of worship”. (The Telegraph)