Four very young children have been stabbed in a park near Lake Annecy, in France’s south-east.
Police overpowered and arrested the attacker, Interior Minister Gérald Darmanin said.
Reports say the children were aged three or younger, and at least two were in a critical condition.
Hours later, local officials have told the BBC the children are in a stable condition.
UK Foreign Secretary James Cleverly said that one of the injured children was a British national. One of the other children is reportedly Dutch.
Police have confirmed that the suspect is a 31-year-old Syrian, who had refugee status in Sweden.