Ukrainian troops were charging through an expanding area of previously Russian-held territory in the east on Friday, making significant territorial gains in a surprise breakthrough that could mark a major turning point in the war.
Kyiv claimed it had retaken more than 1,000 sq km (385 sq miles) of territory in its south and east from Russia in the last week.
President Volodymyr Zelensky said the area had been “liberated” as part of a counteroffensive.
The loss of territory, around Ukraine’s second largest city Kharkiv, was even acknowledged by pro-Russian forces.
“The very fact of a breach of our defences is already a substantial victory for the Ukrainian armed forces,” the head of the Moscow-installed administration for occupied areas in Kharkiv province, Vitaly Ganchev, said on Russian state TV.
Mr Ganchev later said his administration was trying to evacuate civilians from cities including Izium, Russia’s main stronghold and logistics base in the province near the eastern front.
The Russian defence ministry released video of military vehicles speeding along a highway, saying they showed reinforcements rushing to defend the area. The Kremlin declined to comment on the Ukrainian advance.
“The initial signs are positive and we see Ukraine making real, demonstrable progress in a deliberate way,” Antony Blinken, the US secretary of state, said in Brussels the day after visiting Kyiv.
“But this is likely to go on for some significant period of time,” he added. “There are a huge number of Russian forces in Ukraine and unfortunately, tragically, horrifically, President [Vladimir] Putin has demonstrated that he will throw a lot of people into this at huge cost to Russia.”
Ukrainian officials released a parade of videos showing soldiers raising flags and posing in front of street signs in villages and towns across a swathe of previously Russian-held territory.
One viral image showed troops holding up a Ukrainian flag at a highway welcome sign for Kupiansk, previously more than 50km inside Russia’s front line. The city is a vital strategic target as the junction of several of the main railway lines supplying Russian troops at the front.
Western military analysts say the advance could shut the supply lines Moscow has relied on to sustain its force in eastern Ukraine, and potentially leave thousands of Russian troops encircled.
Such rapid advances have largely been unheard of since Russia abandoned its assault on Kyiv in March, shifting the war mainly into a relentless grind along entrenched front lines.
The Ukrainian general staff said that “thanks to skilful and coordinated actions, the Armed Forces of Ukraine, with the support of the local population, advanced almost 50km in three days”.
The surprise Ukrainian breakthrough in the east came a week after Kyiv announced the start of a long-awaited counteroffensive in Kherson province in the south.
Ukrainian officials say Russia moved thousands of troops south to respond to the Kherson advance, leaving other parts of the front line exposed and creating the opportunity for the lightning assault.
“We found a weak spot where the enemy wasn’t ready,” presidential adviser Oleksiy Arestovych said.
