Dozens killed in suspected chemical attack on rebel-held Syrian town

Dozens of people have been killed in what is supected to be a chemical attack in rebel-held northern Syria, in one of the largest mass casualty incidents using a toxic gas in the six-year conflict.

The death toll rose to 67 in the hours after the attack on Khan Sheikhun in Idlib province on Tuesday. Doctors said the victims exhibited symptoms apparently matching those caused by exposure to deadly sarin gas. Scores more people were injured.

The raids were carried out by planes believed to be loyal to the government of Syrian president Bashar al-Assad. Later, a series of airstrikes on the same town targeted a hospital and two emergency response centres that were recovering and treating victims of the initial strike.

The attack came a day after the US ambassador to the UN, Nikki Haley, said the US government was no longer focused on Assad’s removal from office, and as a two-day conference on Syria’s future, hosted by the EU and UN, began in Brussels.

The international chemical weapons watchdog said it was gathering and analysing information. The French foreign minister, Jean-Marc Ayrault, demanded an emergency UN security council meeting.

Khan Sheikhun houses thousands of refugees from the nearby province of Hama who have fled the fighting there.

“In this most recent attack, dozens of children suffocated to death while they slept,” said Ahmad Tarakji, the head of the Syrian American Medical Society, which supports hospitals in opposition-controlled areas in Syria. “This should strike at the very core of our humanity. How much longer will the world fail to respond to these heinous crimes?”

SAMS said its doctors had determined that the symptoms of the patients were consistent with exposure to organic phosphorus compounds like the nerve agent sarin, which is banned by the chemical weapons convention.

The casualties have been distributed across a wide range of hospitals in Idlib, with some sent north towards Turkey. There were reports that casualties driven to the Bab al-Hawa crossing on the Turkish border were experiencing difficulties in entering the country for emergency relief.

Few hospitals in Idlib have the capacity to deal with the symptoms of chemical attacks due to the repeated bombing of medical facilities by forces loyal to the government and lack sufficient oxygen tanks to treat victims.

Idlib is one of the last bastions of rebel control in Syria, and has been subjected to a relentless campaign of aerial bombardment despite a supposed ceasefire brokered earlier this year by Russia and Turkey that was aimed at paving the way for political negotiations.

The raid in Khan Sheikhun indicates Assad’s growing confidence. He has wrested control of territory from the rebels, including the entire city of Aleppo, in recent months. His regime has benefited from the unflinching support of Moscow and Shia militias backed by Iran, as well as waning support for the opposition by its allies in the region and the new US administration.

The attack will refocus attention on the failure of the international community to prevent the worst abuses in Syria’s war, and casts doubt on a signature achievement of Barack Obama’s, which negotiated the presumed destruction of Assad’s chemical arsenal in 2013.

That deal followed a sarin gas attack on eastern Ghouta near Damascus in August 2013 that killed more than 1,000 people and nearly prompted a US intervention in the conflict.

Since then, chemical attacks have continued on a smaller scale, mostly deploying chlorine gas, which was not covered by the deal because it has industrial uses. The deployment of toxic gas on this scale is an escalation of Assad’s war and indicates that his military still retains supplies of banned chemical weapons.

The Syrian opposition described the attack as “appalling” and called on the UN security council to take action.