A lone attacker reportedly drove into and injured 11 pedestrians while shouting "Allahu akbar" — God is great in Arabic — in the city of Dijon, eastern France, on Sunday.
The assailant apparently targeted five different groups of people on the streets over a period of half an hour. Two of the victims are said to be in a serious condition.
A source close to the investigation told AFP that: "The man, born in 1974, is apparently unbalanced and had been in a psychiatric hospital." Yet the French police source added that "for now his motives are still unclear" and confirmed that: "Nine people were lightly injured and two others seriously but their lives do not appear to be in danger."
Interior Minister Bernard Cazeneuve told French media that the man was "very unstable."
On social media, one witness wrote that an 11-year-old was among the injured, and said that at least four of those harmed have several fractures. The onlooker, Théo Souman, also tweeted a picture from the scene.
Other observers said that the attacker referred to the "children of Palestine" as an explanation for his actions, according to Reuters.
Manuel Valls, French prime minister, tweeted to express his solidarity with the victims and their families.
Solidarité à l'égard des victimes de Dijon et soutien aux familles. MV
— Manuel Valls (@manuelvalls)December 21, 2014
This could be only the latest in a series of "lone wolf" attacks, both in France and worldwide. It is feared that many of these are a direct consequence of calls for violence by the Islamic State in countries that are currently involved in a coalition fighting the militants in Iraq and Syria.
Saturday saw another suspected radical Islamist attack in the French town of Joué-lès-Tours. A 20-year-old Burundi-born French national called Bertrand Nzohabonayo reportedly attacked two police officers, slashing one in the face. He apparently also shouted "Allahu akbar" as he acted.
In 2014, the French government estimates that some 1,200 nationals have left the country, or tried to leave, to join the ranks of the Islamic State or al Nusra Front — al Qaeda's Syrian arm.
Meanwhile, last week, provocative French TV presenter and author Eric Zemmour caused controversy after he called for French Muslims to be asked to leave the country. "Now go home," Zemmour said France should be allowed to tell them, before warning of a "civil war between communities."
Zemmour's statements resulted in debate and a huge backlash, with some of his colleagues at RTL radio station — where he presents a twice-weekly program — stating that his opinions "tarnish the values" of the station. The presenter was sacked by 24-hour news channel i-Télé, prompting heated arguments in France over free speech rights.
Follow Sally Hayden on Twitter: @sallyhayd