A Russian-installed official in Ukraine's Kharkiv region said on Monday that Ukrainian forces outnumbered Russian and pro-Russian forces by eight times during a lightning Ukrainian counteroffensive in the region last week.
Speaking to the state-owned Rossiya-24 television channel, Vitaly Ganchev said that Ukrainian forces had captured previously Russian-held settlements in the region's north, breaking through to the border with Russia, and that "about 5000" civilians had been evacuated to Russia.
Ganchev said "the situation is becoming more difficult by the hour", adding that the border with Russia's Belgorod region was now closed.
Battlefield reports could not be immediately verified.
Over the weekend, Ukrainian forces overran the key Russian supply hubs of Izium and Kupiansk, where the Kharkiv region's Russian-appointed administration had been based.
On Sunday, Russia's Defence Ministry published a map, showing that Russian forces had almost entirely abandoned the Kharkiv region.