Police were immediately deployed to the scene and French Interior Minister Gérald Darmanin said in a tweet that the sole suspect was “arrested thanks to the very rapid intervention of the police.”
Ambulances ferried the injured children to a nearby hospital. Local newspaper Le Dauphiné libéré said six children and one adult were injured. At least three of the children were reportedly in critical condition.
Reports said the children were all about three years old and were from a kindergarten class that was playing in the Jardins de l’Europe lakeside park.
The local police chief ordered the area cordoned off and urged the public to stay away. Soldiers blocked access to local roads as police questioned eyewitnesses.
Police were also ordered to set up a security perimeter around the Quai Jules-Philippe school, which is on the opposite side of the canal that flows into Lake Annecy.
President Emmanuel Macron condemned what he called an “absolutely cowardly attack.”
“Children and an adult are between life and death,” he said in a tweet. “The nation is in shock. Our thoughts are with them as well as with their families and the emergency services on the scene.”
The Mayor of Annecy, François Astorg, arrived quickly at the scene of the “terrifying attack.”
“All my thoughts are with the victims and the families,” he said in a tweet.
Some media reports suggested the assailant was a Syrian national born in 1991, but there was no immediate confirmation from the police. One eyewitness told local radio the man was speaking English and clearly targeted the children.
The French National Assembly interrupted a debate on controversial pension reforms to observe a minute’s silence for the victims.
Prime Minister Elisabeth Borne announced that she would travel to Annecy on Thursday. The interior minister was also on his way to the town.