London (AFP) - The Islamic State group is launching fewer chemical weapons attacks in Syria as their Iraqi stronghold in Mosul, where the arms are made, comes under pressure, according to a report out Tuesday.
IS has allegedly used chemical weapons in one attack in Syria this year, on January 8 in Aleppo province, according to global market intelligence firm IHS Markit.
The figure marks a significant fall in such attacks in Syria, where there were 17 allegations of chemical weapons being used by IS in 2016.
By comparison, so far this year the jihadists have carried out 10 chemical weapon attacks in Iraq, of which nine were in Mosul, on a par with the 21 attacks in the country last year.
The focus of 2017 attacks in Mosul suggests that IS has not yet established chemical weapons production sites outside of the city, IHS Markit said.
"Although it is likely that some specialists were evacuated to Syria and retain the expertise," said the firm's analyst Columb Strack.
Iraqi forces launched the battle to retake Mosul in October last year and are now on the cusp of success.
Thousands of people have been killed and hundreds of thousands displaced by fighting since IS overran the city in June 2014.
The jihadists' chemical weapons manufacturing was centred in Mosul and production has been dented by Iraqi forces' campaign to drive IS out of the city, IHS Markit said.
"Nevertheless, the Islamic State probably retains the capability to produce small batches of low quality chlorine and sulphur mustard agents elsewhere," the report said.
Since July 2014, IHS Markit has recorded 41 allegations of IS using chemical weapons