Mustard gas ‘likely used’ in suspected Islamic State attack

Testimony from doctors and experts has added weight to claims that civilians in a town near the northern Syrian city of Aleppo were the victims of an Islamic State attack involving a chemical agent that was most likely mustard gas.

Doctors said the patients, who come from the town of Marea, suffered from skin lesions, respiratory problems and redness in the eyes following a barrage of attacks on Friday. The symptoms were were highly suggestive of exposure to a chemical agent. The evidence raises the prospect, denied by the Pentagon, that Isis has gained access to chemical stockpiles from Syrian president Bashar al-Assad’s regime thought to have been destroyed or degraded. A 2013 accord, brokered by Russia, took Assad’s declared chemicals out of Syria in an 11th-hour move to avert US bombing.

Marea, 50 miles from Aleppo, is a front line between Isis and rebels opposed to Assad. Opposition fighters evicted Isis from Aleppo in 2014, losing more than 1,000 men in the battle, but the terror group has returned with the rebels engaged in a battle for the city with the Assad regime.

Deployment of mustard gas, which remains toxic in an area for a long time, could be intended to render areas of the battlefield inaccessible to opposition fighters. The use of the gas would be a significant escalation in Islamic State’s battle against the rebels and a worrying development in its ability to conduct chemical warfare. But the scale of use appears far less than the regime’s use of chlorine and other banned substances. British officials said they believed Isis had acquired its chemical weapons capability independently.

Pro-opposition media circulated images of the remnants of mortars and accused Isis of perpetrating the attack using chemicals in artillery shells that were fired into the city on Friday.

The Syrian-American Medical Association, which has set up a field hospital in Marea, said 50 civilians showing symptoms of chemical exposure arrived in the facility on Friday following the artillery barrage. They showed initial symptoms that included respiratory problems, redness in the eyes and skin irritations. About 30 of the people developed skin blisters and samples from their blood and clothing as well as the shelling site were taken for further analysis.

The association said in a statement that the agent used was likely to be mustard gas and that local sources “suspect Isis forces of conducting the attack”. In a statement on Tuesday, Medecins Sans Frontieres (MSF) said doctors treated four patients exhibiting symptoms of exposure to chemical agents on Friday in Aleppo province, including two children, one aged three and a five-day-old baby, but did not ascribe responsibility for the attack.

MSF, citing testimony by the family, said a mortar shell hit their home after which yellow gas filled their living room. “Personally, I’ve never encountered these symptoms before, and clinical features and the evolution in time were highly suggestive of intoxication by a chemical agent,” said an MSF doctor, who requested anonymity. “I think we are never prepared to face this kind of atrocities among civilian population and children. As medics, we are trained to react in difficult and stressful situations, but events like this are overwhelming.”

One source said: “It’s not that significant. We are bombing Isis daily. We are training people to fight them on the ground. It’s just a different kind of weapon and it’s not as if they care about their reputation. Even the Assad regime had some desire to conceal what they were doing. It’s another sign of how dangerous Isis is – but it doesn’t change a lot.”

Pentagon officials said they had seen no “confirmable link” indicating that Isis had unleashed a chemical attack on Aleppo. They did not firmly rule it out and a spokesperson condemned such an attack as “abhorrent” if found to have occurred.

It is unclear where Isis was able to obtain the alleged mustard agent, although experts said it was likely to have been seized from degraded, undeclared, weapons stockpiles owned by the Syrian regime. Isis might have also seized materials from Iraq – where the militant group controls large swathes of territory – which were left over from Saddam Hussein’s chemical weapons programme. But such stocks would likely have been far too degraded to be more than crudely effective.

Other possibilities, according to former chemical weapons inspectors, include Isis affiliates in Libya smuggling Muammar Gadafy’s mustard-filled shells or precursor chemicals or Isis compelling scientists in its Iraqi or Syrian territorial holdings to manufacture the toxic chemicals.

Following a sarin gas attack on the Damascus suburb of Ghouta in 2013, which was widely blamed on the Assad regime, Syria acceded to the chemical weapons convention under a deal brokered by Russia and the US that stipulated destruction of its chemical weapons stockpile.

In August 2014, the Organisation for the Prohibition of Chemical Weapons said that all of Syria’s declared category 1 stockpiles, which included mustard agent, had been destroyed. The total amount was approximately 1,040 tonnes.

But the actual amount of sulfur mustard, commonly known as mustard gas, was a tiny percentage. A presentation delivered in December last year by Dominique Anelli, the OPCW’s demilitarisation chief, said that just 20 tonnes of sulfur mustard had been declared by the Syrian government and subsequently destroyed by the chemical weapons watchdog.

However, western intelligence assessments in the past had concluded that Syria possessed much larger consignments of mustard gas. A French intelligence report shortly after the Ghouta attacks in 2013 estimated that Syria had "several hundreds tons of sulfur mustard, stockpiled in its final form". That would leave significant amounts of mustard gas unaccounted for, some of which could have been seized by Isis. – Guardian service