Those killed included civilians and former Iraqi forces
It has been confirmed that the Islamic State killed 232 people near Mosul on Wednesday.
Those killed included civilians as well as former Iraqi forces who refused to comply with orders.
A United Nations spokesperson has said that the IS has abducted nearly 8000 families or "tens of thousands" of people from around around the city.
The civilians are understood to have been brought into Mosul and used as human shields nearby to military installations.
Earlier in the week, UN human rights spokesman Rupert Colville spoke about information his officials had begun receiving.
It described the IS "deliberately using civilians as human shields, forcing them to move to sites where ISIL (another name for IS) fighters are based, or preventing them from leaving other places for strategic reasons".
IS is battling US-backed Iraqi and Kurdish forces advancing on Mosul, which is the country's second-largest city and the militants' last urban stronghold in Iraq.
The offensive started last week.
Days ago, IS launched a surprise assault in and around Kirkuk, a Kurdish-controlled northern city some 170km (100m) southeast of the front lines of Mosul.
The UN has expressed concern over the mass movement of people that is now taking place, as displaced civilians attempt to flee the fighting.