Ukrainian forces have been pushed out of one village in Russia's border region but Kyiv's forces are still probing along the front, a senior Russian commander says, more than nine days since the lightning incursion into Russia.
The biggest foreign attack on sovereign Russian territory since World War II unfurled on August 6 when thousands of Ukrainian troops smashed through Russia's western border in an embarrassment for the Russian top military brass.
Ukrainian President Volodymyr Zelenskiy said on Wednesday his forces had advanced a few kilometres and the goal of replenishing an 'exchange fund' of prisoners of war was being achieved.
Kyiv was carving out a buffer zone to protect its population against attack, one Ukrainian official said.
Major General Apti Alaudinov, who commands Chechnya's Akhmat special forces in Kursk, said Russian forces had forced out Ukraine from Martynovka about 18km from the border.
"We have burned everything that moves, everything that we have been able to find," Alaudinov told Russian state television, reminding viewers of Russia's defeat of Napoleon's 1812 invasion of Russia.
Alaudinov, a close ally of Chechen President Ramzan Kadyrov, said Ukraine was sending in more forces into the region but the shift in resources was weakening Ukrainian forces at other parts of the front.
"The enemy is pushing, he is trying to get through from everywhere, push through," Alaudinov said, admitting initiative was still with Ukraine.
"But every day the enemy's forces are melting."
The Russian town of Sudzha, a transhipment hub for Russian natural gas flowing to Europe via Ukraine, was not under full Ukrainian control, he said.
Ukraine said it was fully under Ukrainian control.
Ukraine's incursion appears aimed at forcing Moscow to slow its advance along the rest of the front inside Ukraine, though the Russian defence ministry also reported intense battles along the Ukraine front and said its troops had taken better positions at several points.
Ukraine said there was no sign Russian military pressure was receding along the eastern front inside its borders on Thursday and reported the heaviest fighting in weeks near Pokrovsk.
Supported by swarms of drones, heavy artillery and tanks, Ukrainian units have carved out a sliver of the world's biggest nuclear power and battles were ongoing along a front about 18km inside Russian territory on Thursday.
Kursk's acting governor, Alexei Smirnov, said the Glushkov district, which has a population of 20,000, was being evacuated.
At least 200,000 people have been evacuated from the border regions, according to Russian data.
Kremlin deputy chief of staff, Sergei Kiriyenko, visited Kurchatov, the town servicing the Kursk nuclear power station which is just 40km from the fighting.
While the Ukrainian attack has embarrassed Moscow, revealed the weakness of its border defences and changed the public narrative of the war, Russian officials said what they cast as a Ukrainian "invasion" would not change the course of the war.
Russia, which invaded Ukraine in 2022, has been advancing for most of the year along the 1000km front in Ukraine and has a vast numerical superiority.
The Ukrainian incursion into Russia has yielded its biggest battlefield gains since 2022.
The West, which backs Ukraine and has said it will not allow President Vladimir Putin to win the war, has repeatedly said it knew nothing of the Ukrainian plans to attack Russia, statements that Moscow officials reject.
Putin said on Monday that Ukraine "with the help of its Western masters" was aiming to improve Kyiv's negotiating position before possible peace talks.
Russia's defence ministry published footage it said showed a Russian drone destroying a US-made Stryker armoured combat vehicle in the Kursk region.
Russian officials have warned if Western weapons were used on Russian territory then Moscow would consider that a grave escalation.
By bringing the war to Russia, Zelenskiy risks weakening Kyiv's defences along the front in Ukraine while Russia has already sent in thousands of reserves to expel the Ukrainian soldiers.
If Ukraine wants to hold the Russian territory it has taken, it will need to build a sophisticated logistics operation to support its forces, military analysts say.
