Izium, Ukraine (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.