A military operation to retake the Islamic State stronghold of Falluja has been announced by the Iraqi Prime Minister.

Haider al-Abadi, leader of the west Asian state, said on Twitter that "zero hour" for the liberation of Falluja had arrived.

"The moment of great victory has drawn near and Daesh has no choice but to flee", he said.

Falluja was the first city to fall to IS in 2014 and is one of only two of its remaining strongholds in Iraq.

Iraq's military has already warned civilians to leave the town. They told state TV that those who could not flee should raise a white flag above their homes.

Currently, the military, police and volunteer fighters effectively surround the city, about 65 km (40 miles) west of Baghdad, the Iraqi capital.