According to a report leaked by Organisation For The Prohibition of Chemical Weapons (OPCW) on Thursday, a chemical agent known as mustard gas was used in the Syrian town of Marea, located to the north of Aleppo, a hotspot for clashes between DAESH and Syrian rebels.
The report does not mention DAESH directly as the party responsible for the use of chemical weapons, however, some diplomatic sources have pointed to DAESH.
"It raises the major question of where the sulfur mustard came from," one source said. "Either they (DAESH) gained the ability to make it themselves, or it may have come from an undeclared stockpile overtaken by DAESH. Both are worrying options."
US State Department spokesman John Kirby said the OPCW presented three reports to member states on Oct. 29, adding "two of these reports are very disturbing. The OPCW has confirmed (chemical weapons) use in one investigation, and concluded likely use in a second."
Kirby, referring to the forenamed report, added that aside from 'mustard gas' additional chemical agents may also have been used. He stated that the OPCW confirmed that toxic chemicals, probably containing chlorine, were used in opposition-controlled territory in Idlib Province.
"Witnesses reported hearing helicopters overhead at the time the chemical munitions exploded. Only the Assad regime has helicopters," he said
According to a report presented to UN Secretary General Ban Ki-Moon earlier this month, some evidence shows that it is not just Assad regime that has access to chemical weapons.
"If it is determined that a non-state actor such as ISIL was also using chemical weapons, such use would be consistent with ISIL’s record of complete disregard for human rights and international norms and values," Kirby said,
Mustard gas -which causes severe delayed burns to the eyes, skin and lungs - is a Schedule 1 chemical agent, meaning it has a few uses outside of warfare.
Another report released by the OPCW says that they have been unable to get information from the Assad regime confirming regime forces have been targeted by insurgents using chemical weapons.
Eastern Ghouta massacre
In a report released by the UK based Syrian Network for Human Rights (SNHR) on the second anniversary of the eastern Ghouta chemical massacre, committed by Assad forces, in which 1,127 people suffocated to death on August 21 2013, Syrian regime used gases likely to be poisonous a total of 28 times.
In the report published by SNHR, the head and founder of SNHR Fadel Abdul Ghani said ‘’there is plenty of evidence that indicates that the party responsible for these violations is the Syrian government which owns the aviation force, toxic gases, and heavy weaponry."
"Therefore, resolution 2,235 tends to show procrastination signs and gives additional time for criminals to perpetrate more crimes. Government forces meet all Security Council resolutions with contempt and indifference midst committing more breaches and violations,’’ Ghani added.
SNHR stated that the chemical attacks conducted by regime forces targeted the areas held by opposition forces.
According to the report, 97 percent of the toxic gas was used against opposition forces and 3 percent was used against DAESH.