The website of the small town Dieulefit, near Grenoble, was taken over last weekend. Instead of the welcome page, visitors saw videos and text praising Jihadist Muslims.
A picture of a man wearing a balaclava and holding a gun was also displayed, with an song in Arabic playing in the background.
Hackers managed to take control of the site for two days before the town could do anything.
In the same weekend, websites for academies in Reims and Nanteuil-le-Haudouin, north east of Paris, were also hacked in a similar manner.
All three attacks have been reported to the authorities, who are taking the incidents very seriously. The Group HP-Hack has already hit several French websites in the past, and is known to police.
In 2011 numerous websites in France fell victim to a hacker based in Algeria – about 10 police websites were taken over, as well as that of the Prime Minister at the time.