Smoke billows in a part of West Mosul, where Iraqi security forces are fighting ISIS, Iraq June 21, 2017.

:: A suicide bomber blew himself up on Friday among civilians fleeing Mosul’s Old City, where Iraqi forces are gaining ground against ISIS militants mounting a fierce but desperate defense, officers said.

Ahmed Hashem, a major and medic in the Iraqi army speaking to AFP from a field hospital, said the attack took place in the Mashahda neighborhood of the Old City.

“We received 12 people killed and more than 20 wounded in our field hospital, including women and children,” he said.

A colonel in the army’s 16th infantry division said it was difficult to get a definitive casualty toll because the area where the attack happened was not fully cleared.

“The suicide bomber infiltrated a group of displaced people and blew himself up among them before reaching our troops,” he said.

Thousands of civilians have fled the Old City of Mosul since Iraqi forces launched their most perilous assault yet against the Islamic State group.

Around 100,000 more remain trapped by the militants, who have made human shields a key element in their defense of the Old City, their last redoubt in Iraq’s second city.

The security forces have been wary of Iraqi ISIS members attempting to flee the Old City death trap by blending in with the population, while the Chechen, French and other foreign jihadists stay behind to mount a suicidal last stand.