MOSUL — An Iraqi officer says a "major" Islamic State group counterattack is taking place along the northern edge of Mosul's Old City.

The attack has pushed Iraqi Army forces back some 75 meters (82 yards) and is threatening recent gains in other Old City fronts, he says.

The officer said the attack was launched just after noon Friday and estimated it was carried out by 50 to 100 ISIS fighters.

A doctor at a medic station said he received more than a dozen wounded Iraqi soldiers.

Both men spoke on condition of anonymity in line with regulations.

Iraqi security forces have retaken almost all of Mosul — Iraq's second largest city — from IS militants who overran it in 2014.

While IS-held territory shrunk to less than one kilometer squared, the group continues to remain capable of launching counterattacks against Iraqi forces and insurgent attacks deep inside government-held territory.