The Washington Post says Ukrainian forces have reportedly seized about 100 square kilometers inside Russia in a massive cross-border attack.
The Ukrainian military has carried out attacks in Russia’s western border region of Kursk since Tuesday.
The US newspaper reported in its digital edition on Thursday that an adviser to Ukrainian President Volodymyr Zelenskyy had confirmed the Ukrainian military activity inside Russia and the seizure of land.
The newspaper quoted the adviser as saying that Ukrainian personnel took hundreds of prisoners and captured a key facility that Russia uses to send gas to European countries.
Independent Russian media on Thursday reported on a video purportedly recorded by residents of Kursk that shows them asking President Vladimir Putin for help.
The residents said the president has been misinformed about the situation on the ground and that such lies lead to death.
They contradicted Chief of the General Staff of the Russian Armed Forces Valery Gerasimov, who recently said the situation is under control. The residents said heavy fighting is ongoing.
Meanwhile, the governor of the Russian region of Lipetsk, neighboring Kursk, said on Friday that explosives were blown up in a Ukrainian drone attack. The governor said nine people were listed as injured.
The Ukrainian military announced that it had struck warehouses containing guided aerial bombs and other facilities near a Russian military airfield in Lipetsk.
Ukraine has continued its attacks on Russian territory, while Russia has intensified its assaults in eastern Ukraine and elsewhere.