"We are horrified by this attack and we trust the French authorities to shed full light on this tragedy and bring the perpetrators of these murders to justice," Israeli foreign ministry spokesman Yigal Palmor told AFP on Monday.

Police in France said the shooting had left victims, but there was no official toll yet in the incident, which saw a man on a motorbike open fire on a group of people standing outside the school in the southwestern city.

Last week in the same region, three paratroopers were also shot dead by a man on a motorbike.

Police launched a major manhunt in the wake of that attack, but the perpetrator has yet to be apprehended. Between 50 and 60 police officers, including anti-terrorist specialists, have been drafted in to the investigation.

Senior military officials have ordered troops based in the region not to wear their uniforms outside barracks.