Iraqi forces have launched an operation to reclaim the city of Falluja from the so-called Islamic State.
Counter-terrorism forces, backed by Shi'ite militias on the ground and coalition airstrikes, are moving into the city on several fronts.
Explosions and gunfire have been heard in Falluja's southern Naimiya district, while an assault to recapture Saqlawiya town has also begun.
It is being reported the army is facing resistance from IS fighters in the form of suicide and car bombings.
Officials have kept short a full attack on the city to give civilians time to flee.
Hadi al-Amiri said: "One of the obstacles delaying the assault on Falluja is our concern over the safety of civilians in Falluja. We have urged people inside Falluja to leave the city to spare them and we will do our utmost to protect them."
"We may even delay the assault on the city for several days to give people more time to leave," he added.
It is feared as many as 50,000 civilians may still be trapped inside.
The UN have reported people starving to death in the city and being killed for refusing to fight for IS.
Falluja is located almost 40 miles west of Baghdad, and was the first city to fall to so-called Islamic State, in January 2014.