Report: Islamic State manufacturing arms on industrial scale

Soldiers with Iraq's elite counterterrorism forces secure houses and streets during fighting against Islamic State militants to regain control of the eastern neighborhoods of Mosul, Iraq, Tuesday, Dec. 13, 2016. (AP Photo/Hadi Mizban) (The Associated Press)

Civilians welcome Iraq's elite counterterrorism forces after an operation to liberate them from Islamic State militants at a recently liberated neighborhood in Mosul, Iraq, Tuesday, Dec. 13, 2016. (AP Photo/Hadi Mizban) (The Associated Press)

An arms research group says Islamic State militants have been manufacturing weapons in and around Mosul on an industrial scale, with products largely purchased in bulk from Turkey.

The report by the London-based Conflict Armaments Research was released on Wednesday. It's based on the study of IS weapons found at manufacturing facilities and on the battlefield during the Iraqi operation to retake Mosul.

As Iraqi forces retake more territory from IS, the extremists are losing the capacity to manufacture weapons, but the research group's executive director James Bevan warned that IS will take much of its weapons-making expertise with it as its most well-trained fighters flee.

The massive operation to retake Mosul was launched in October and since then, Iraqi forces have retaken less than a quarter of the city.