Samples obtained by French intelligence show that forces loyal to Syrian President Bashar al-Assad "undoubtedly" used sarin nerve gas in an April 4 attack in northern Syria, France's foreign minister says, citing a declassified report.
The attack in the town of Khan Sheikhoun killed scores of people and prompted the United States to launch a cruise missile strike on a Syrian air base in response, its first direct assault on the Assad government in the conflict.
"We know, from a certain source, that the process of fabrication of the samples taken is typical of the method developed in Syrian laboratories," Jean-Marc Ayrault told reporters.
"This method is the signature of the regime and it is what enables us to establish the responsibility of the attack. We know because we kept samples from previous attacks that we were able to use for comparison."
The six-page report - drawn up by France's military and foreign intelligence services and seen by Reuters - said it was able to reach its conclusion based on samples they had obtained from the impact strike on the ground, and a blood sample from a victim.
Among the elements found in the samples were hexamine, a hallmark of sarin produced by the Syrian government.
"The French intelligence services consider that only Bashar al-Assad and some of his most influential entourage can give the order to use chemical weapons," the report said.
It added that jihadist groups in the area did not have the capacity to develop and launch such an attack and that Islamic State was not in the region.
Assad's claim to AFP news agency on April 13 that the attack was fabricated, was "not credible" given the mass flows of casualties in a short space of time arriving in Syrian and Turkish hospitals as well as the sheer quantity of online activity showing people with neurotoxic symptoms, the report said.
