A global watchdog,Organisation for the Prohibition of Chemical Weapons, has warned of ISIS making its own chemical arms and already having used them in Iraq and Syria.
The organisation's head, Ahmed Uzumcu, reportedly claimed of finding evidence of the use of sulphur mustard in attacks in the two war-torn countries.
"Although they could not attribute this to Daesh... there are strong suspicions that they may have used it (chemical weapons)," Uzumcu told AFP, using the alternative name for the jihadist group.
What is more worrying, according to Uzumcu, are the suspicions of the organisation producing the weapons themselves.
This hints of ISIS possessing the technology, know-how and also access to materials which might be used for the production of chemical weapons.
Evidences in place
CIA director John Brennan in February told CBS News that IS fighters had the capability to make small quantities of chlorine and mustard gas.
Also as per SANA, the state news agency, IS mounted a deadly gas attack against Syrian troops at a government-controlled airbase outside the divided eastern city of Deir Ezzor.
The attack was the latest in a string of suspected mustard gas attacks by the jihadists in Syria and neighbouring Iraq.
On 9 March, a suspected IS gas attack on the Iraqi town of Taza, south of Kirkuk, killed three children and wounded 1,500 others, with injuries ranging from burns to rashes and respiratory problems.
While chemical agents allegedly used by IS so far have been among its least effective weapons, the psychological impact on civilians is considerable.
A total of 25,000 people fled their homes in and around Taza last month, fearing another attack.
Uzumcu also urged vigilance by other nations to guard against any chemical attack outside Syria and Iraq.