PARIS A poison gas attack in a rebel-held suburb of Damascus last month is inspiring foreign militants to go and fight for vengeance in Syria, France's top anti-terrorism judge said on Wednesday, warning of long-term security consequences.
Footage of victims was seen around the world and U.S. officials say more than 1,400 civilians, including hundreds of children, were killed in the August 21 attack that U.N. investigators said used the sarin nerve agent.
United States, Britain and France have said President Bashar al-Assad's forces were responsible. Syria and Russia blame the rebels fighting to topple him.
Marc Trevidic, France's most senior examining judge in charge of investigating terrorism, said such images had pushed would-be fighters to join what they saw as jihad, or holy war.
"It's a driving factor," he said on the sidelines of a terrorism conference in Paris. Asked about the impact of the August attack, he said "that has boosted" the numbers of aspiring jihadists.
Even before the attack, officials in Western countries had been concerned that the civil war was drawing in foreigners eager to fight.
The French Interior Ministry estimates about 120 French nationals are in Syria, with another 50 trying to get there.
Trevidic said the presence of French fighters in Syria represented a long-term threat for France when they come back with training, having fought alongside hardened militants.
"If they are not able to set up an Islamic state in Syria, they'll come back disappointed," he added.