The allegation that a nerve agent leaked from a warehouse controlled by rebels in the Syrian province of Idlib has been dismissed by experts in the industry.
The deadly chemical attack in the southern Syrian province of Idlib that killed at least 100 people was likely carried out by Bashar al Assad's regime forces, experts told TRT World.
Claims made by Russia, the key backer of the regime, that blamed opposition rebels for the deaths caused by the nerve agent are not true.
"I don't buy the Russian story that they hit a weapons depot," said Gwyn Winfield, the editorial director at CBRNe World, a periodical focusing on threats posed by chemical explosives.
"It doesn't fit with rest of the narrative we have of the continuous use of things like chlorine and other chemical agents by the Syrian regime over the last 4 to 5 years."
Chemical weapons have been used several times in the six-year Syrian conflict between rebels and Assad's regime.
Residents in Idlib's rebel-held town of Khan Shaykhun found themselves gasping for air on Tuesday morning after rockets were fired by regime jets, witnesses say.
What unfolded on the streets was heart-wrenching: the lifeless bodies of children packed on the back of a truck, half-dressed people foaming at the mouth and struggling to breathe, a man holding his two dead infants.
First responders and doctors said the victims showed symptoms consistent with exposure to nerve agents, such as the sarin gas.
An autopsy of the bodies carried out by experts in Turkey, where many of the injured have been moved for treatment, confirmed that sarin was indeed used.
Sarin is a deadly chemical that can kill people within minutes after contact.
Exposure to just a milligramme of the substance causes the body to lose control over muscles, making them rigid and leading to asphyxiation.
Its use in warfare is banned.
Medical staff of the NGO Doctors Without Borders who examined eight victims also said they saw symptoms – constricted pupils and muscle spasms – that are consistent with exposure to a neurotoxin, such as sarin gas.
Shortly after the attack, Russia's military said Syrian regime jets had struck a depot in Khan Shaykhun where rebels stored weapons, suggesting the nerve agent was hidden there.
Experts began pointing out errors in that claim right from the start.
The Russian Ministry of Defence said the jets carried out the strike between 11:30am and 12:30pm on Tuesday.
But the first reports of the incident started to come out hours before, at the break of dawn.
Experts also point out that it's very unlikely that chemicals stored in a warehouse could react to form sarin or any other nerve agent after being hit by rockets.
"Aerial bombardment of a warehouse allegedly containing ingredients for chemical warfare is not likely to be the explanation for what happened," Dan Kaszeta, a former US Army Chemical Corps officer, told TRT World.
A place where chemical components for sarin are stored "would go up in a ball of flame -- a very large one," if attacked either from the air or ground, he said.
Nerve agents have to be used shortly after they are made because once mixed they do not have a long shelf life, he said.
The technology of making nerve gas that can be preserved in artillery shells or rockets for a longer period is difficult to come up with, said Kaszeta.
"It seems unlikely to me that some rebel faction had the ability to make a higher grade of nerve agent than the regime itself, which has 40 years of expertise."
Investigations into previous chemical attacks have shown that the Syrian regime made sarin just days before its use.
The attack in Khan Shaykhun is the deadliest since Augusst 2013, when hundreds of people were killed in a sarin attack in eastern Ghouta near Damascus.
Many blamed the Assad regime for that assault.
Daesh is known to have used chemical weapons in the region in the past but they have been less lethal warfare agents, like mustard gas, says Winfield.
"They have yet to show the ability to synthesise sarin. They certainly lack the ability to transport the agent."
Making and transporting sarin is a complicated process that needs sophisticated facilities and expert handling.
"We have basically seen continuous use of chemical weapons on both sides. The world and politicians seem to have been helpless in trying to stop it," Winfield said.
"I don't think they are going to be very successful in stopping them now."
Author: Saad Hasan