(CNN) France has said that it has proof that the Syrian government was behind a chemical weapons attack in Syria earlier this month that killed 89 people.
The French Foreign Minister Jean-Marc Ayrault said that samples taken from the attack on the rebel-held town of Khan Sheikhoun matched those from a previous incident.
“We have definite sources that the procedure used to make the Sarin sampled is typical of the methods developed in Syrian laboratories,” he said. “This method bears the signature of the regime, and that is what has allowed us to establish its responsibility in this attack.”
French laboratories had stored samples taken from other chemical attacks in Syria and so were able to compare them, he said.
A tweet posted by the French Foreign Ministry said: “There’s no doubt that Sarin was used. There is also no doubt about the responsibility of the Syrian regime.”
The attack has been widely blamed by Western powers on the Syrian government, which is supposed to have given up its chemical weapon stockpile in 2013 following an attack in the Ghouta area of Damascus that activists say killed 1,400 people.
International chemical weapons inspectors from the Organization for the Prohibition of Chemical Weapons (OPCW) said last week they had found “incontrovertible” evidence that Sarin, or a similar substance, was used in the April 4 attack on Khan Sheikhoun, but did not apportion responsibility.