Exclusive by Rebecca Wright, Sam Kiley, Olha Konovalova and Peter Rudden, CNN
(CNN) - Burned-out tanks and trucks emblazoned with Russia's signature 'Z' symbol lie at the side of the road, gutted and red with new rust. A collapsed bridge is covered in signs warning of landmines. Further along, the wreckage of a car is left alongside a destroyed petrol station surrounded by the debris of shelling.
These are the signs of Ukrainian victory and, for now, a Russian rout.
As CNN became the first international television crew to enter Izium since the Ukrainians retook it on Saturday, the team encountered a city just waking up to its new reality: that six months of occupation is over.
Izium has now been "liberated," along with almost the whole of Kharkiv region, a Ukrainian military source told CNN. The city is a huge strategic loss for the Russian military, which used it as a key base and resupply route for its forces in eastern Ukraine, and shows the speed and scale of Ukraine's lightning-fast counteroffensive in the northeast.
Combined with a parallel offensive in the south, Ukraine has taken back a total of 6,000 square kilometers (about 2,300 square miles) of land, President Volodymyr Zelensky said Monday. Russia said the retreat of its troops from the region was "tactical," in order to focus resources on the Donbas area.
In Izium, work is still ongoing to make the city center completely safe. The Ukrainians are seeking to capture a few Russian soldiers still in hiding, and anyone who worked with them during the occupation. The city also remains in a complete information blackout, with no phone or data signal -- a tactic used by the Russians across the occupied territories.
From what the CNN team witnessed, local people are relieved to see their city back in Ukrainian hands.
Although the streets of Izium were largely quiet, residents would occasionally venture out of their homes and wave at CNN's vehicles or at the passing military trucks, and shake hands with any Ukrainian soldiers they came across.
But at the same time, fear of the Russians still grips the city. Most of the residents CNN approached were too scared to speak freely about what had happened there in recent months.
One couple in their fifties agreed to talk, using only their first names.
They have been celebrating the Ukrainian victory over the city, Valeriy said, calling it a "balm for the soul."
"We prayed to God to be liberated without a fight and without blood. And so it happened," he said.
The distant sound of shelling is a constant reminder that despite the impressive gains in this counteroffensive, the war is not yet won -- and many parts of Ukraine are still within range of Russia's arsenal of heavy weapons.
But slowly, the Ukrainians are working to restore Izium and the other recaptured territories to something approaching normal.
During CNN's visit, a group of Ukrainian soldiers barreled up triumphantly in a steaming tank. With obvious glee, they quickly hitched it to a Russian self-propelled artillery vehicle, abandoned intact by retreating Russians. The weapon is among the most powerful in Russia's armory and will be repurposed for Ukraine's counteroffensive.
When asked if it was a tough fight to retake the city, the tank driver who drove off with the howitzer replied, "Not really."
The Ukrainians have gained a huge weaponry haul from these battles in the northeast, as many Russian troops sacrificed their vehicles intact in order to escape with their lives.
Inside the abandoned Russian command center
One of the final showdowns in the battle for Izium, according to the Ukrainian military, took place in a former school which was being used as a Russian troop base. The Russians had surrounded the building with deep trenches, sand bags and armored vehicles.
The building has now been gutted, with piles of red bricks and radiators tangled with broken windows and collapsed timber from the roof. Next to the building lies the shell of a red truck on its side, carrying the 'Z' logo of Russian forces.
Further down the road is the building that those troops were trying to protect: the Russian command center, hidden in a subterranean bunker beneath a disused factory.
Rows of mismatched school desks lined the gloomy basement, with job titles attached on white labels -- including the commanders of air defense, artillery, intelligence, and state security, along with lower-ranking titles such as "duty officer." Nearby, the Ukrainian troops are still finding booby traps that were left to protect their lair -- including a trip wire with a grenade attached.
Another bleak concrete room opposite the command center served as the sleeping quarters, with old wooden doors placed horizontally on piles of bricks or jerry cans to create makeshift beds. The retreating troops had apparently left in a hurry, with clothes, toothpaste and papers left scattered on the floor and the beds.
One Ukrainian soldier showed CNN the green rotary phone that the troops had left behind. "Russian technology!" he sneered -- in English.
Above ground, the Russians also left piles of ammunition.
Along with the loss of weaponry, and the humiliating retreat captured on multiple videos and shared across social media, one military official tells CNN that a large number of Russian prisoners of war have been taken by Ukraine.
Ukrainian soldiers were victorious in spirit as they drove through the city, waving from their newly acquired tanks and trucks, many of them with the tell-tale 'Z' already painted over.
'Who have we come to liberate here?'
Izium resident Valeriy said the locals in the city were angry with the Russians for their behavior.
"Where there were no people, (the Russians) stole everything," Valeriy said. "They lived like pigs. We entered one house -- and pigs live better."
Valeriy said the fighting in Izium began on March 4, when eight Grad rockets landed near their home, which was "frightening" but luckily did not hit them directly. Their next-door neighbor's house was destroyed by one of the rockets, but she survived without a scratch.
He said the Russian troops who arrived in the city early in the war quickly realized that Russian President Vladimir Putin's justification for the invasion -- to "de-Nazify" Ukraine -- was a lie.
"A (Russian) artilleryman came and said 'Father, we saved you from the Nazis,'" Valeriy said. "And I said to them, 'Show me one.'"
Valeriy said he spoke to the young soldiers in Russian and tried to make them see that they were destroying the once-close relationship Ukrainians and Russians held, particularly in this part of the country which is so close to the border.
"I told them they destroyed a man's house, and he was from the Kursk region (of Russia)," Valeriy said. "Everyone here has relatives in Belgorod (in Russia) and other cities."
He said at one point, Russian reconnaissance forces came to him and asked, "Who have we come to liberate here?"
That confusion and sense of disillusionment from among the Russian ground troops was likely a major factor in their retreat from this region in the past week.
But more dangerous to Putin is that the command-and-control system of his army collapsed in Kharkiv province. Those high-ranking officers fled their bunker, while their men abandoned their heavy weapons as they fled.
Ukraine's forces will try to keep them on the run and perhaps hope, one day, they return to Moscow with the story of what happened in Kharkiv and demand a reckoning from their leaders.
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