Baghdad, May 23 (IANS): An offensive to retake the besieged city of Fallujah from Islamic State has begun, Iraqi PM Haider al-Abadi announced on Sunday. Local residents have been told to evacuate via secured routes.

“Zero hour for the liberation of Falluja has arrived. The moment of great victory has drawn near and IS has no choice but to flee,” Abadi posted on his Twitter account, the RT online reported.

The Iraqi offensive will see the army, police counterterrorism units, local tribal fighters, and a coalition of Shiite Muslim militias join forces. Meanwhile, air support will most likely be provided by the US-led coalition.

Local residents were given the heads up by the Iraqi army earlier. “The citizens who are still in Fallujah (should) be prepared to leave the city through secured routes that will be announced later,” the army said in a statement released on Facebook.

Those families who cannot leave the besieged city are to raise white flags to mark their location in the city, the army added.

There will be three corridors opened for civilians and camps set up the west, southwest, and southeast of the city, Deputy District Council Chairman Falih al-Essawi said.

“Our goal is to liberate civilians from IS's repression and terrorism,” Abadi stated in a televised address.

Falluja is an Islamic State stronghold located 50 km west of Baghdad. It was the first city captured by the extremist group back in January 2014.