Aymam Al Mosuli was also believed to be chief of special security units of ISIS. Mysterious death squads have been targeting jihadi warlords prompting rumours they could be “Special Forces” waging a guerrilla war on ISIS.

ISIS have been desperately holding on to the northern Iraq stronghold as Kurdish Peshmerga and Iraqi army forces pound the twisted terrorists. But the squeeze on ISIS means the group are resorting to more desperate – and deadly – measures.

So-called "suicide squads" are reportedly flooding into Mosul to clash with Iraqi troops. The terrorists coming from neighbouring Syria stand out from regular terrorists due to their "distinctive uniforms".

The suicide squads are made up of foreign fighters, armed with light weapons and all wearing suicide belts, witnesses claim.

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