More than half of those who have fled Mosul and its surroundings are children and the United Nations is concerned that those still in Daesh-controlled areas would be more exposed than ever before.
Iraqi forces, backed by Western airstrikes, are battling the jihadists in the west of the city after recapturing the eastern side earlier this year.
Iraqi authorities have accused Islamic State (IS) militants of using "toxic chemical material" in the battle for Mosul, but they say it has had little effect and that the campaign to liberate Iraq's second-largest city is continuing.
Al-Nuri mosque is a significant target as it is where IS leader Abu Bakr al-Baghdadi first appeared after the declaration of caliphate across parts of Iraq and Syria in 2014.
"The bombs used by the Iraqi air force in Mosul are laser-guided and used when we ascertain the nature of the target", Hammah said, Baghdad Post reported.
Troops have had the centuries-old mosque with its leaning minaret in their sights since last month.
Iraqi forces and the US-led coalition supporting them "are nearing the end of the operation to recapture Mosul", said Patrick Martin, Iraq analyst at the Institute for the Study of War.
"The sheer volume of civilians still fleeing Mosul city is staggering", Grande said.
"Mosul has pushed us to our operational limits", said Grande.
March 28: The UN says more than 300 civilians have been killed since the start of the west Mosul operation.
Two special forces units - the Counter-Terrorism Service and the Rapid Response Division - have spearheaded the fighting inside Mosul, while soldiers and police have also taken part.
The narrow alleyways restricts the use of suicide cars by the militants and tanks, armoured personnel carriers and Humvees by the government forces.
Residents who have managed to escape from the Old City have said there is nearly nothing to eat but flour mixed with water and boiled wheat grain.