At least 10 people were injured on Monday evening when a man drove a van into a crowded Christmas market in Nantes, western France. Five people including the driver suffered serious injuries and one of the victims was in a critical state, police said.
After mowing down shoppers and passers-by in the popular square in the centre of the city, the driver stabbed himself several times with a knife, according to the interior ministry.
A ministry spokesman said it was too early to determine the man's motives. Nantes prosecutor Brigitte Lamy told reporters on the scene that he had made no religious claim and appeared to have acted alone.
Local newspaper Ouest France reported, citing a police officer and witnesses, that the driver shouted "Allahu Akbar" ("God is greatest" in Arabic). But several witnesses denied to the news agency Reuters that he uttered those words.
The incident comes a day after a man rammed his car into crowds of pedestrians in the eastern city of Dijon, injuring at least 11 people and shouting “Allahu Akbar".
According to a state prosecutor, the man had a long history of severe mental illness and no links to terrorism. Marie-Christine Tarrare said the man, aged 40, had been admitted to hospital for psychiatric problems 157 times since 2001.
On Saturday a man was shot after he stabbed and wounded three police officers in central France while yelling the same words.
France is on high alert for attacks on its soil following calls from Islamic State (Isis) militants to target the citizens of countries attacking Isis positions in Iraq.