Saturday’s retreat marked the most significant gain for Ukraine’s military since they defeated a Russian attempt to capture the capital, Kyiv, in March. Ukrainian forces, backed by increasingly powerful Western weapons, have seized hundreds of square miles of territory from Russian control over the past four days in the Kharkiv region as the Russian line collapsed. Analysis: How Ukraine Pierced Russia’s Defense Images on social media showed triumphant soldiers replacing Russian flags with the colors of yellow and blue in villages, towns and cities as they fell under Ukrainian control after months of Russian occupation. Ukraine’s top commander said more cities would follow as he watched a flag-raising ceremony, accompanied by the national anthem, in the small town of Banaklia, which was one of the first to be recaptured. “I’m sure this is not the last city,” said General Oleksandr Syrskyi, dressed in full combat gear. “Ahead of us is Kupiansk, which is already half occupied by our troops. Ahead of us is Izyium and many others.” Pictures have emerged of the Ukrainian flag flying over Kupiansk, which has been an important logistics hub for Russia to send supplies to its troops in the critical southeastern Donbass region. Images have also been posted on social media of Ukrainian troops at the gate of Izyium – the main stronghold of Russian forces in the region. It was a city captured by Russia in the first weeks of the war and had remained under Russian control ever since – until now. Explaining the Russian withdrawal, Defense Ministry spokesman Igor Konashenkov said Russian troops would regroup from the Balaklia and Izium regions in the Donetsk region of the Donbass. Mr. Konashenkov said the move is being made “to achieve the stated goals of the special military operation to liberate Donbas.” Read more: Royal Navy shadowing Russian warships Zelensky calls for nuclear demilitarization Image: An abandoned Russian military vehicle in Hrakove village in Kharkiv Russian retreat ‘like an avalanche’ The withdrawal claim for a gathering in Donbas is similar to the justification Russia gave for withdrawing its forces from the Kiev region and northern Ukraine earlier this year. This was after they faced fierce Ukrainian resistance, aided by Western weapons. The developments came amid what has been largely a media blackout over Ukraine’s aggressive plans. The Ukrainian military said it had launched a long-awaited counter-offensive against Russian-held territory in the southern Kherson region on August 29. It has blocked journalists’ access to the front lines, so the progress of this operation has been difficult to measure. However, in the previous days – the UK Ministry of Defense said the start date was September 6 – Ukrainian forces simultaneously began attacking Russian-held positions in the Kharkiv region. Claims of significant progress in Kharkiv began to emerge in the past three days. Vladislav Sokolov, the Russian-appointed head of the local administration, said on social media that authorities in Izyum had begun evacuating residents to Russia. Ukrainian Defense Minister Oleksii Reznikov told Ukraina TV channel that the Russians had no food or fuel for their troops in the region as Kyiv had cut off their supply lines “It will be like an avalanche,” he said, predicting a Russian comeback. “A line of defense will shake and fall.” Ukrainian President Volodymyr Zelenskyy said in a nightly video address on Friday that Ukrainian troops have recaptured more than 30 settlements in the Kharkiv region since the counteroffensive began. “We are gradually taking control of more settlements, returning the Ukrainian flag and protection for our people,” Mr Zelensky said.