In the meantime the United States has admitted that at least 105 Iraqi civilians were killed in an air strike it carried out in Mosul in March.
US Central Command (CENTCOM) said it had targeted two snipers from so-called Islamic State (IS) with what it called a precision-guided munition.
CENTCOM said the strike detonated explosives that militants had placed in the building.
Civilians sheltering in the lower floors were killed when it collapsed.
In another incident, 35 civilians were killed on Thursday in us-led coalition air strikes in an Eastern Syrian town.