Iraqi Prime Minister Haider al-Abadi announced on Monday the start of a military operation to liberate Falluja from the ISIL Takfiri group.

Iraqi Prime Minister Haider al-Abadi announced on Monday the start of a military operation to liberate Falluja from the ISIL Takfiri group.

In a televised speech, Abadi said that military, police and volunteer fighters known as Popular Mobilization Forces (PMF) are taking part in the operation.

"Zero hour for the liberation of Falluja has arrived. The moment of great victory has drawn near," he said, adding that ISIL had "no choice but to flee."

Abadi's overnight announcement came hours after Iraq's military implored residents of ISIS-held Falluja to flee their homes ahead of the operation to wrest the metropolis from the terror group.

"I am calling for citizens who are inside Falluja to leave their areas and head towards safe corridors," military spokesman Brig. Gen. Yahya Rasoul said on Iraqi TV. "In the coming few days, the operations to liberate Falluja will be launched."

Iraqi planes have dropped thousands of leaflets -- safe passage cards -- on Falluja, according to a statement from Iraq's Joint Operations Command.

Reuters news agency quoted Deputy District Council Chairman Falih al-Essawi as saying that three corridors would be opened for civilians to camps west, southwest and southeast of the city, and a subsequent military statement said some residents had begun to flee.

"Our goal is to liberate civilians from Daesh's repression and terrorism," Abadi said in his speech.

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

The allied forces have virtually surrounded the city, about 65 km (40 miles) west of Baghdad.

The Baghdad-based pro-Kurdish news website Shafaq said on Sunday that close to 20,000 police troops had arrived on the outskirts of Falluja ahead of the expected assault.