With the fall of massive areas in northern and western Iraq, ISIS was able to control a key area north of Baghdad that used to produce chemical weapons under Saddam. However, the site was empty. The UN inspection teams had destroyed and cleared the site completely from the industrial tools and the main materials that could be used to make chemical or biological weapons, according to the UN teams’ reports.

When the US led alliance started to bomb ISIS positions in Iraq and in Syria after August 2014, ISIS lost its momentum in Iraq. Since October, ISIS has suffered a series of defeats on every front in Iraq. This weakened position could explain why ISIS chemical ambitions have been recently renewed.

In late January 2015 in one of ISIS bomb-making factories in Mosul, something went wrong while preparing a chlorine bomb. “ISIS members informed the nearby residents to close their doors and windows. They said a gas leak was caused by an air raid. But there were no air raids…people were panicked,” said Maouris Milton, a blogger from Mosul.

A few days later, On January 29, ISIS tried to extract some chemical and poisonous waste buried carefully by UN teams in Tikrit. But the concrete structure around the burial site stood as an obstacle despite numerous attempts to destroy it with explosives, Hashimi recalled.