ANNECY, (France): A Syrian refugee armed with a knife stabbed four preschool children and injured two adults by a lake in the French Alps on Thursday in an attack whose motive remains unclear.

The youngest victim in the quiet town of Annecy was just 22 months old and investigators are trying to understand the reasons for the frenzied rampage in a sunny public park at around 9:45 am (0745 GMT).

The attacker, dressed in black and carrying a blade around 10 centimetres (four inches) long, could be heard shouting “in the name of Jesus Christ” on a video taken by a bystander and seen by AFP.