HARI SREENIVASAN: But first: It’s been more than five weeks since Iraqi forces, backed by airstrikes from the U.S.-led coalition, began the campaign to retake Mosul from ISIS.
The city is the largest in either Iraq or Syria still held by the militants, and the fight to retake it has been vicious.
Special correspondent Jane Ferguson and videographer Alessandro Pavone have spent the last several days with Iraqi special forces inside the city, and sent us this report.
JANE FERGUSON: Searching for enemy movement, Maj. Ziad Al Gubere leads his squad of fighters.
On the radio, reports that several ISIS gunmen are rushing this front-line position. His men are ready. They have pushed this far into Mosul city, and, from a mosque, Iraq’s special forces fight off counterattacks.
MAJ. ZIAD AL GUBERE, Iraq Military: You see these guys?
JANE FERGUSON: “A fighter just blew himself up just over there,” he tells us.
This tangle of wreckage is all that separates his soldiers from the suicide bombers. This is as far as the front line comes here in Mosul in this neighborhood, just this pile of rubble, beyond it, ISIS fighters.
Taking Mosul from ISIS is the toughest mission these men have ever faced. Brutal street-to-street fighting pushed the militants from this area just days go.
So, this was a marketplace here in this neighborhood of Mosul. The fighters here tell us that there was a heavy battle with ISIS fighters here. Their bodies are still strewn around the area.
Iraqi forces are facing an enemy that embraces and celebrates death, and in a nearby house, we are suddenly told more ISIS fighters are approaching. Major Ziad orders his men onto the roof, and the fight begins.
ISIS fighters are just in the building right next door to us here. And the Iraqi special forces are exchanging fire with them.
JANE FERGUSON: This kind of fighting on the front line is happening every day right now in Mosul now.
MAN: (through translator): In the neighborhood in front of us, there is a group of ISIS fighters, plus a car bomb. They always try to send car bombs.
JANE FERGUSON: When the fighting eases, civilians appear from their houses on the street outside. One soldier proudly shows us his loot he’s poached from ISIS: uniforms and memorabilia of the Islamic State.
Further down the street, Major Ziad sees more ISIS fighters. He calls for a mortar strike. On this tablet, they can pinpoint targets in the city. With so many civilians still in their homes, there is no room for error.
They then race to the rooftop to get a better view. The front line snakes through the streets around us. ISIS fighters can come from many sides. Two mortars hit buildings nearby.
Can you tell us, what are the main dangers in this battle?
MAJ. ZIAD AL GUBERE (through translator): The most dangerous thing ISIS is using is the car bomb. Also they have a new style, using drone-carried bombs. They can control them with the remote. They use a small amount of explosives. They target our cars and groups of us.
JANE FERGUSON: ISIS had two years to plan its defense, and the group spent that time innovating its tactics and weapons. Thick armor envelops car bombs. Bullets cannot penetrate them, so suicidal drivers tear towards Iraqi fighters, seen here in an ISIS propaganda video.
In this urban environment, cars can appear from around corners just yards away, so crude barricades have been erected, and civilians banned from driving. If any car approaches, these soldiers shoot. And ISIS is not only deadly above ground. An elaborate network of underground passageways allow their fighters to creep up behind advancing forces and shoot at them.
Hidden below, they can hide from U.S. coalition airstrikes. During the battle, ISIS fighters wouldn’t just move around through here. They could also live in these tunnels. You can see they have been sleeping all along this one. They even have gas lanterns left and uniforms here.
Digging machines, like this one captured by Iraqi forces, are what ISIS is using to make the tunnels, giving themselves an advantage in the urban environment. Even after their retreat, ISIS is able to inflict casualties. They rig houses with booby-traps and leave hidden bombs across this city, causing devastating injuries to soldiers and slowing the army’s advance.
Abdullah Ali’s job in the bomb disposal unit just cost him his eye. A hidden bomb exploded on him last week when he opened the front door of a house.
ABDULLAH ALI, Iraq Military (through translator): ISIS planted it in the house. I tried to clear the house, so a family could return to it. And then I got hit.
JANE FERGUSON: Outnumbered and outgunned, ISIS’ bomb-making tactics are a way to compensate.
ABDULLAH ALI (through translator): Of course, the ISIS’ main plan is to use bombs and car bombs and IEDs. They don’t have military power, so they depend on them.
JANE FERGUSON: The people living in Mosul are also used by ISIS as cover, around a million are still in the city, on the front line of a war that rages around them.
And with so many families still sheltering inside their homes, airstrikes risk killing the innocent. While the Iraqi army battled ISIS fighters in these streets, the people here waited and prayed for days for it to be over.
This family had been hiding inside their house. Like so many families in Mosul, they have found themselves on the front line caught between ISIS and the Iraqi army.
Food finally arrived with these government handouts, and residents poured into the streets to get help. There is a steady stream of civilians fleeing the city, with nothing but homemade white flags as a flimsy signal that they mean no harm.
Some are loaded onto trucks bound for refugee camps. Others simply walk, hoping to find help. It’s a treacherous journey. Villages like this outside Mosul have now really just become transit points. Others fleeing from further inside the city move through here to make it to camps.
There is still fighting ongoing even out here on the outskirts of the city. American involvement in this war is not so visible in Mosul City, but it is hugely significant. Over 5,000 U.S. troops are present in Iraq, training and advising Iraqis.
U.S. airstrikes, artillery, rockets and special forces are giving crucial support to the army’s advance. In control-and-command centers, American and Iraqi military leaders monitor the battle together.
U.S. Army Colonel Brett Sylvia is the commanding officer at Camp Swift Base outside Mosul.
COL. BRETT SYLVIA, U.S. Army: The progress was very fast in being able to get to Mosul, and predictably, it slows down when you hit this dense urban area.
But, still, every single day, they make forward progress. but regardless of how long it takes, it’s not a question of if Mosul will be liberated, but just a question of when.
JANE FERGUSON: The American military is giving them as much of a battleground advantage as they can, but Iraqi soldiers will still have to fight their way through the city’s treacherous streets. Men like Major Ziad and his troops have a long and dangerous battle ahead.
For the “PBS NewsHour,” I’m Jane Ferguson in Mosul, Iraq.