The women and other victims are believed to have been killed on alleged charges of disloyalty to the caliphate, espionage or refusal to swear allegiance to Daesh.
Mosul is the largest city under the control of Daesh. It is 400 km (250 miles) north of Baghdad and it has been selected by the government as the next target for Iraq's armed forces after they won back the western city of Ramadi.
Iraqi Prime Minister Haider al-Abadi said on Monday that Islamic State would be defeated in 2016 with the army preparing to move on Mosul. “We are coming to liberate Mosul and it will be the fatal and final blow to Daesh,” he said in speech praising the army's victory in Ramadi.