The attack, which happened in the French alpine town of Annecy, was carried out by a Syrian national with legal refugee status in France, a police official told Reuters.

“Children and one adult are between life and death. The nation is in shock,” French President Emmanuel Macron said in a statement on Twitter, calling the attack “an act of absolute cowardice”.

French Interior minister Gerald Darmanin said on Twitter that attacker had been arrested.

Two children and one adult are in life-threatening condition, while two children were slightly hurt, police said.

Witnesses said at least one child involved was in a stroller.

BFM TV showed footage of several policemen overpowering an individual in a park.

“Nothing more abominable than to attack children,” French national assembly speaker Yael Braun-Pivet said on Twitter. The French parliament observed a minute of silence to mark the incident.

(Reporting by Benoit Van Overstraeten, Geert De Clercq and Juliette Jabkhiro; writing by Geert De Clercq and Silvia Aloisi; Editing by Toby Chopra)