The attacks, in September and October, “caused painful burns to at least seven people consistent with exposure to low levels of a chemical warfare agent known as ‘vesicants,’ or blister agents,” reads the report published Friday.
The town of Qayyara, 60 kilometres south of Mosul, was liberated by Iraqi forces in late August.
Launching the chemical weapons is one of many tactics designed for maximum damage and casualties that ISIS has employed as it loses territory.
As the militants retreated from Qayyara, they set at least five oil wells on fire and left crude oil oozing through the town’s streets, burning homes and coughing thick smoke into the air.
In Mishraq, two people died and hundreds were treated for respiratory ailments after ISIS set fire to a sulfur plant in a last stand for that town.
The extremist group has famously rigged homes and ordinary objects with hundreds of improvised explosives designed to create havoc for the liberating forces and returning civilians.
“As ISIS fighters flee, they have been repeatedly attacking and endangering the civilians they left behind, increasing concerns for residents of Mosul and other contested areas,” said Lama Fakih, Human Rights Watch’s deputy Middle East director.
Reports indicate that ISIS dug trenches in Mosul and filled them with crude oil, ready to set on fire as part of their defence of the city.
In the investigation of the chemical attacks in Qayyara, residents told Human Rights Watch that the attacks occurred when Iraqi forces were in full control of the town and they believed the militants were trying to force the civilians to retreat with them.
In the first of three attacks documented by the monitoring group, a projectile landed in the garden of a family’s home on September 21, “oozing a liquid that caused burns and blistering to two family members and two policemen who helped them remove it.”
The second attack took place on October 6 when a projectile struck in front of a café, severely burning two fighters in the area.
The third attack, on October 10, saw a refinery worker burned and blistered after a projectile landed in front of a refinery.
An independent expert contacted by Human Rights Watch, Keith B. Ward, concluded that the victims had been exposed to a blistering agent such as sulfur mustard. Further investigation is needed to conclude the agents used in the attacks, the report noted.
The use of such blister agents is a war crime under international law.
