According to humanitarian groups, doctors in Syria have been treating patients showing signs of exposure to chemical agents. The patients were from the town of Marea, which has experienced recent bombardment.
In a press release on Tuesday, Doctors Without Borders (Medecins Sans Frontiers, MSF) said it treated four members of the same family who showed "symptoms of exposure to chemical agents" on August 21.
The MSF statement said a man and a woman with their three-year-old girl and a five-day-old newborn came to a hospital run by MSF in the Syrian province of Aleppo.
The family was "suffering from respiratory difficulties, inflamed skin, red eyes, and conjunctivitis," MSF said, and within three hours they developed blisters and had increased breathing problems."
The parents in the family told MSF that their home in Marea (pictured above) in Aleppo province had been hit by a motor shell on the evening of August 21 and that their living room began filling with a yellow gas. After first being taken to a local hospital, the family was referred to the MSF facility as their condition worsened.
MSF's program manager for Syria, Pablo Marco, said that while MSF could provide no laboratory evidence that would determine the cause of the family's symptoms, "the patients' clinical symptoms, the way these symptoms changed over time, and the patients' testimony about the circumstances of the poisoning all point to exposure to a chemical agent."
On Sunday, the Syrian American Medical Society (SAMS) said in a press release that it had treated over 50 civilians suffering symptoms that indicated chemical exposure.
"Roughly 23 civilians developed skin blisters, with doctors identifying the agent to be mustard gas," SAMS said.
The statement from SAMS added that samples had been taken "patient blood, clothing, and hair as well from the shelling site" for further assessment.
SAMS runs a variety of medical facilities and specialty care clinics in Syria.
The AFP news organization has reported on speculation among journalists and activists in Syria that the so-called "Islamic State" (IS) could be behind mustard gas attacks in Syria.
Two weeks ago, US officials indicated to American media outlets that it was possible that IS was using mustard gas against Kurdish fighters in Iraq and Syria. While there has been no word from US officials that IS has been targeting Syrian civilians with mustard gas, the chemical agent's alleged use against Kurdish fighters would at least indicate IS was capable of such attacks.