Iraqi forces have entered Mosul for the first time since 2014, a milestone in the effort to reclaim the city.
Baghdad said its troops had breached the eastern suburbs of the Islamic State’s last major urban stronghold in Iraq after two weeks of combat.
Special forces also took control of the local state television building.
“This is a good sign for the people of Mosul because the battle to liberate Mosul has effectively begun,” General Talib Shaghati said.
Mosul was conquered in a lightning Isis advance in mid-2014, falling to the militants along with much of the surrounding Nineveh plains.
Two weeks ago Iraq announced a major campaign to liberate the city, the last in a line of urban bastions that had been taken by Isis and reclaimed over the past year, including Tikrit, Ramadi, and Fallujah.
The fighting is moving from sparsely populated villages on the outskirts of Mosul to heavily mined terrain inside the city. Observers expect heavy street fighting and urban combat.
Speaking by telephone from the eastern edge of the city, a Mosul resident said mortars were falling on civilian areas.
“Mortars have been falling throughout the day. Two hit our yard, two outside our house and one hit the back of the house. Everyone is hiding under the staircase.
“Because of the intensity of the fighting we have not been able to eat anything. It is too dangerous to go and fetch food. The world is being destroyed around us.
“I have never seen this level of fighting. There are still around 40,000 civilians in my neighbourhood. Last night fighting was for two hours but today [Isis] fought from 7.30am until an hour ago. In our street I think there are still around 300 people. There is no electricity and running water right now.”
His wife said: “We have not eaten anything today. Our future is lost and we don’t know what is going to happen to us. I wish these mortars and airstrikes would stop because there are too many civilians in our neighbourhood.”
The battle for Mosul will be the toughest yet for Iraqi forces, who are supported by Kurdish Peshmerga soldiers and Sunni tribal fighters. Shia militia have been tasked with blocking a potential retreat for the militants into the eastern desert of Syria.
The coalition is backed by American air power and military advisers.
It’s estimated there are 1-2 million civilians inside Mosul, by far the largest city under Isis control and a key flank of its diminishing caliphate.
Concerns have mounted over the fate of the civilians, with Isis accused of using them as human shields to slow the alliance’s advance. The UN expects tens of thousands to flee the fighting in the coming weeks.
Isis is believed to have 5-6000 fighters holed up in the city, though US officials have said in recent days that senior leaders were attempting to flee.