AL QAYYARAH, IRAQ - NOVEMBER 09:  A firefighter works to extinguish an oil well set on fire by fleeing ISIS members on November 9, 2016 in Al Qayyarah, Iraq. Many families have begun returning to their homes in recently liberated towns south of Mosul. Oil wells in the area that were set on fire by ISIS continue to burn blanketing the area in think clouds of smoke and oil.  (Photo by Chris McGrath/Getty Images)
CNN  — 

Suicide bombs and street-to-street fighting, human shields and a humanitarian crisis. The battle to recapture Mosul from ISIS has been raging for a month. So where do things stand?

Are Iraqi-led forces close to victory, or are the militants digging in for a lengthy and dogged war of attrition?

The battle

Iraqi special forces soldiers move in formation in an alley on the outskirts of Mosul.

Mosul is ISIS’s last major stronghold in Iraq – and the terror group has shown that it is willing to go to almost any lengths to keep hold of it, using everything from suicide bombs to booby-trapped toys in its desperate fight.

ISIS has had months to prepare for the offensive – building tunnels, constructing explosives, rigging abandoned houses to detonate and plotting counterattacks; reinforcements were reportedly brought in from Raqqa in Syria to help defend the city.

The conflict is “not a conventional war,” according to Iraq’s former foreign minister, Hoshyar Zebari.

A drone operator from the Iraqi special forces watches his aircraft in Mosul's Karkukli neighborhood.

And even as areas are swept clean of ISIS fighters, the battle is not over: It will take months to clear the terrorists’ former territory of IEDs.

“They put them on the road, in the houses. We liberate a village and they are everywhere – people come back to their homes, open a door or even a refrigerator and it blows up,” says Brig. Gen. Bajat Mzuri of Zeravani Special Forces.

A Peshmerga fighter holds part of a defused bomb planted by ISIS militants in Bashiqa, east of Mosul.

Things are even more complicated in the city itself, where ambushes are common. A CNN team was trapped inside Mosul for more than 24 hours when an Iraqi convoy was attacked and surrounded, leaving them unable to retreat.

An estimated 100,000 troops, including Iraqi soldiers, Peshmerga fighters, Sunni tribal paramilitaries and Christian and Turkmen militias are involved in the offensive, though not all are on the front line. Hundreds of airstrikes have been carried out by the US and others in support of the coalition.

READ MORE: Inside Mosul: Tunnels, resistance, terror

The gains

Iraqi soldiers come under fire from ISIS fighters as they try to push forward in Karkukli, Mosul.

Iraqi-led forces entered Mosul on November 3, after more than two weeks fighting their way across the plains to the east of the city, through nearby towns and suburbs.

They have liberated the ancient Assyrian village of Nimrud – where historic artifacts were largely destroyed by ISIS militants last year.

And in recent days, the Hashd al Shaabi paramilitary forces have recaptured a key airbase near Tal Afar, 70 kilometers (43 miles) west of Mosul.

An Iraqi army officer looks at a damaged carved stone slab, destroyed by ISIS militants, in Nimrud.

But it has not all been good news.

Inside Mosul, the coalition is meeting fierce resistance, and an ISIS counterattack on the Mosul suburb of al Zahraa, a week after it was recaptured, left at least two dead.

An audio message, purportedly from ISIS leader Abu Bakr al-Baghdadi, has been credited with emboldening the group’s fighters, and inspiring them to keep up their resistance.

Peshmerga spokesman Brig. Gen. Halgurd Hikmet told CNN this week that “for ISIS, Mosul is survival” – they will not give the city up easily.

An Iraqi soldier checks a mass grave in Hamam al-Alil, an area recently retaken from ISIS.

Along with their gains, coalition fighters have made countless grim discoveries, including mass graves, bodies stuffed into wells and others hanging from lampposts, all attesting to ISIS’s brutal resolve.

READ MORE: Teen sculpts Nimrud’s ruined artifacts

Those who stayed

When ISIS took control of Mosul in 2014, about half of the city’s 2 million residents fled, but many stayed on, afraid of leaving their homes for an uncertain future.

As the offensive began, human rights groups and NGOs warned that 1.2 million Iraqis in the region were in “grave danger” as ISIS and the coalition faced off.

Hundreds of people living in ISIS-controlled villages outside Mosul were rounded up and taken into the city to be used as human shields as Iraqi troops and Peshmerga closed in.

A woman cries as she tries to find family photos after returning to her home in the newly-liberated town of Bartella.

The Iraqi Security Forces have used radio broadcasts and leaflets airdropped into the city to urge civilians to stay where they are.

Others are simply too scared to leave – dozens of civilians have been killed, either deliberately targeted by militants, accused of collaboration with the ISF or caught in the crossfire.

Iraqi children watch a man who fled the fighting being questioned by soldiers at a base near Al-Intissar.

Save the Children estimates that 600,000 children remain trapped inside Mosul; boys as young as 9 are being kidnapped by ISIS and forced to fight on the terror group’s behalf, according to the United Nations.

In outlying villages where ISIS forces have been routed, citizens celebrated their liberation by shaving off their beards and smoking – things banned while their homes were under ISIS control.