Two families on a cycle ride in Toulon, southern France, came under violent attack after assailants hurled insults at two female partners for wearing shorts, according to prosecutors.
The attack, carried out by a group of youths from a housing estate in the Mediterranean port town, has sparked claims that parts of France are prey to an Islamist "morality police".
Two couples with their three children and a friend were on a Sunday afternoon outing on bikes and roller blades when the "incredibly violent" attack took place, according to Var-Matin, the local newspaper.
They were passing near the Cite des Oeillets, an estate in eastern Toulon, when a group of adolescents starting insulting the women of the group because of their shorts, including jibes such as: "Dirty whore, get naked."
When their male partners intervened, a larger group of youths arrived and a fight ensued, according to Toulon prosecutor Bernard Marchal.
"The male partners had simply asked them to respect their women and that sparked the fight. The three men were violently beaten on the face in front of their children. This was provocation of a sexual nature with the intention of forcing a reaction out of the men present," said Mr Marchal.
One of the men was severely beaten and has had to take a month off work, while another had his nose broken. The women were lightly injured and the children suffered from shock.
After accessing CCTV footage, police were able to identify and arrest two suspects, aged 17 and 19, and a preliminary investigation has been launched to identify other suspects.
The attack comes a month after an 18-year-old girl was spat at and insulted by a group of girls who found her shorts indecent. Maud Vallet posted a Facebook picture of herself in shock afterwards with the caption: "Hello, I'm a slag". The post received over 81,000 "likes", or signs of readers's anger and sadness over the incident.
She recounted asking her taunters: "Why are you calling me a whore because I'm wearing shorts while a man can walk around the centre of town bare-chested without anyone saying anything?" She said they replied: "Because you're a woman and should respect yourself, you idiot."
A solidarity "march in shorts" was held in the town. Both incidents follow a summer of tensions over burkini bans in a number of French beach towns.