Iraqi government forces have pushed into the area around a highly symbolic mosque in western Mosul where the Islamic State group's leader made his first and only public appearance.
Black smoke billowed from the area around al-Nuri mosque, also known as the Great Mosque, on Sunday as helicopters hovered overhead and fired into the militants' positions.
At least two large mushroom clouds were seen rising from what is believed to be suicide car bomb explosions as gunfire rattled.
The IS leader Abu Bakr al-Baghdadi delivered a Friday sermon in al-Nuri mosque in July 2014 after the extremist group seized almost a third of Iraq and declared an Islamic "Caliphate" on territory it controlled in Iraq and neighbouring Syria.
