The New York Times | 21 Nov 2016
WASHINGTON — The Islamic State has used chemical weapons, including chlorine and sulfur mustard agents, at least 52 times on the battlefield in Syria and Iraq since it swept to power in 2014, according to a new independent analysis.
More than one-third of those chemical attacks have come in and around Mosul, the Islamic State stronghold in northern Iraq, according to the assessment by the IHS Conflict Monitor, a London-based intelligence collection and analysis service.
The IHS conclusions, which are based on local news reports, social media and Islamic State propaganda, mark the broadest compilation of chemical attacks in the conflict. American and Iraqi military officials have expressed growing alarm over the prospect of additional chemical attacks as the allies press to regain both Mosul and Raqqa, the Islamic State capital in Syria.