A declassified French intelligence report said forces owing allegiance to Syrian President Bashar al-Assad had carried out the alleged sarin nerve gas attack on April 4 in the country’s northern region, Reuters reported on Wednesday. Assad or members of his administration were reported to have ordered the deadly attack.

The six-page document said its findings were based on samples obtained from the chemical strike site and a blood sample from a victim. “We know, from a certain source, that the process of fabrication of the samples taken is typical of the method developed in Syrian laboratories,” Foreign Minister Jean-Marc Ayrault told reporters. Ayrault said this method was a “signature of the regime”. We know because we kept samples from previous attacks that we were able to use for comparison, Ayrault said after presenting the report’s conclusion to the Cabinet.

Dismissing the role of jihadist groups in the chemical attack, the report said, “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 declassified French intelligence report refuted Assad’s claim that the gas attack was fabricated. It cited “mass flows of casualties in Syrian and Turkish hospitals” as well as social media posts showing people with neurotoxic symptoms.

Assad, however, had denied allegations that his forces were responsible for the chemical attack. On April 25, the United States had blacklisted 271 Syrian chemists and employees of a government research centre as punishment for the country’s alleged role in the recent chemical attack that killed nearly 100 civilians in Khan Sheikhoun in the rebel-held Idlib province. Inclusion in the financial blacklist meant the assets belonging to these individuals in the US will be frozen and people and businesses in the country will be barred from dealing with them.

On April 7, the US military had carried out targeted missile strikes on a Syrian base in response to the April 4 chemical attack. The Syrian Army had said the strike had killed six troops and caused “big material losses”. Hours before launching the missile strike, US President Donald Trump had said that the poison gas attack had “crossed a lot of lines” for him.

Assad’s ally, Russia, has claimed that chemical air strike was triggered from a depot controlled by rebels, Reuters reported.