At least 58 people were killed in a suspected chemical attack in Syria, AFP reported on Tuesday, quoting the Syrian Observatory for Human Rights. Dozens were injured in the strike in a town held by rebels in the central province of Idlib. Medical workers and activists said the clinics where the injured were being treated were later targeted by airstrikes, BBC reported.

It is not clear yet whether the attacks in Khan Sheikhoun were carried out by Syrian government forces or Russian troops. However, Italy’s Federica Mogherini, who is the high representative of the European Union for Foreign Affairs and Security Policy, said Bashar al-Assad’s troops were responsible for the “awful chemical’ attack”, according to AFP. A United Nations commission is investigating the chemical attack.

“Everyone is horrified and the children are in total shock,” said Mohammad Hassoun, a spokesperson for civil defence rescue workers in the nearby Sarmin town. He said around 14 injured were brought to Sarmin, and they were bleeding from the nose and mouth. “The total number of wounded is incredible, so far it’s over 200,” The Guardian reported. Several others are suffering from respiratory trouble and other symptoms, including vomiting, fainting and foaming at the mouth, the observatory said, according to AFP.

Though the government has held that it has never used chemical weapons against the rebels, investigations have revealed otherwise. In October 2016, the United Nations and the Organisation for the Prohibition of Chemical Weapons said the government forces used chlorine at least three times between 2014 and 2015. Islamic State fighters have also used the blister agent sulphur mustard in the war, the investigators said.

In September 2016, the Syrian government was accused of dropping barrel bombs containing chlorine that killed more than 80 civilians in the Sukari area of Aleppo.