Volodymyr Zelenskyy has acknowledged his forces are fighting in Russia for the first time.
The Ukrainian president said Kyiv’s incursion into Russia’s Kursk region was part of a drive to restore justice after Moscow invaded in 2022.
Moscow said Ukrainian forces had pushed into the Kursk region last Tuesday and Russian military bloggers said they made some headway, but claimed the situation has since stabilised.
On Wednesday Moscow’s top general, Valery Gerasimov, said the attacks had been halted, but Russia has so far failed to repel the Ukrainian forces from its territory.
Russia has announced it has increased security measures in the border regions of Kursk, Belgorod and Bryansk. The measures allow the government to relocate residents, control phone communications and requisition vehicles.
In a video posted on social media on Friday, soldiers purporting to be from the 61st Brigade holding a Ukrainian flag appeared to be standing outside a Gazprom facility in the Russian town of Sudzha.
“Everything is calm in the town,” they say, adding: “All the buildings are safe, strategic object of Gazprom in Sudzha is under the control of the 99th Mechanised Battalion.”
On Sunday, officials in Kursk said 13 people were injured in the city after debris from a destroyed Ukrainian missile fell on to a nine-storey residential building.
Kursk’s acting governor, Alexei Smirnov, has ordered local authorities to speed up the evacuation of civilians in areas at risk.
On Saturday more than 76,000 people had been evacuated, according to Russia’s TASS state news agency.
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A Russian military helicopter fires following Ukraine’s incursion. Pic: Reuters
Zelenskyy vows to restore justice
In his nightly video address, Mr Zelenskyy vowed to restore justice for Russia’s invasion.
He said he had discussed the operation with top Ukrainian military officer Oleksandr Syrskyi, saying: “Today, I received several reports from commander-in-chief Syrskyi regarding the front lines and our actions to push the war on to the aggressor’s territory.
“Ukraine is proving that it can indeed restore justice and ensure the necessary pressure on the aggressor.”
A Ukrainian serviceman riding in an infantry fighting vehicle near the Russian border. Pic: Reuters
Russia attacks Ukrainian capital
It comes as Russia launched an air attack on Kyiv early on Sunday.
Air defence systems on the outskirts of the city repelled the attacks, Kyiv mayor Vitali Klitschko said.
“Air defence units operating, air raid alert continues,” he wrote on Telegram.
A man and his four-year-old son were killed in the attack and three others wounded, Ukraine’s emergency services said on Telegram, according to Reuters.
A 13-year-old child was among those injured, it added.