Iraqi forces were on Wednesday pushing deeper into the bastion of ISIL Takfiri group, with a commander saying the liberation of Fallujah was days away.

Iraqi forces were on Wednesday pushing deeper into the bastion of ISIL Takfiri group, with a commander saying the liberation of Fallujah was days away.

After securing the southern edge of the city Sunday, Iraqi special forces entered the neighborhood of Shuhada Wednesday morning, Maj Gen Hadi Zayid Kassar, deputy commander of the counter-terrorism forces in Fallujah told The Associated Press.

Artillery and rocket fire cleared the way and a single column of black Humvees was seen moving in between the low rise buildings of Shuhada, a southern neighborhood in Fallujah, AP said. After Iraqi forces began their advance, a quick succession of coalition airstrikes followed, filling the sky above Fallujah with dark grey smoke.

Lt Gen Abdel Wahab al-Saadi told AFP that the Iraqi forces are advancing towards the center of Fallujah.

"The security forces are advancing towards central Fallujah from the southern side but doing so cautiously, to preserve civilian lives," al-Saadi said.

"In the coming days, we will declare the liberation of Fallujah," said Saadi, overall commander of the operation launched on May 22-23 to retake the Takfiri bastion west of Baghdad.

For its part, the Joint Operations Command admitted that progress was being slowed by the astounding number of improvised explosive devices laid by ISIL in the city.

"There are tunnels and between 150 and 200 bombs are defused every 100 meters (yards)," it said in a statement.

"Our information is that ISIL has prepared car bombs, which they are hiding in homes with the intention of attacking us when we enter," the operations command said.

Volunteer forces known as Hashd al-Shaabi (Popular Mobilization) have so far operated on the periphery of the city. Earlier on Monday they stressed that they would not move into the city but in case a decision is take by Prime Minister Haider al-Abadi to do so.