Russian volunteers fighting for Ukraine drove tanks and armoured vehicles across the border into Russia, “capturing” a number of villages.
The daring cross-border assault appeared to be the most significant effort by Ukraine-backed forces to bring the war to Russian soil.
The raid was carried out by anti-Kremlin fighters from the so-called Russian Freedom Legion (RFL) and Russian Volunteer Corps (RDK), which both claim to be in the ranks of Kyiv’s legion of foreign fighters.
A spokesman for Ukraine’s military intelligence said the two volunteer battalions crossed into the Belgorod region to “create a security zone” to protect Ukrainian civilians from Russian attacks.
Russian officials claimed that the “Ukrainian forces” had captured at least four settlements near the frontier amid reports of heavy fighting in the area.
Footage shared on social media appeared to show at least one tank and multiple armoured vehicles with Ukrainian tactical markings approaching the Grayvoron border-control post that had been damaged by earlier shelling.
It was claimed artillery and mortar fire had been used to pummel the position as the volunteer battalions made their advance.
The nearby villages of Kozinka, Glotove and Gora-Podil were also reportedly seized by the Ukrainian-backed forces.
In a social-media taunt, Ukrainian sources shared an image of three soldiers proclaiming a new “Belgorod’s People’s Republic”.
Earlier, the Baza Telegram channel, which has links to Russia’s security services, published drone footage appearing to show a column of Ukrainian vehicles advancing on the checkpoint.
As the fighting erupted, the RDK confirmed its troops had crossed the border and called on residents in the Russian frontier regions to stay at home and “not to resist”.
Meanwhile, the RFL published a video on its Telegram channel calling on Russians to rise up and defeat Vladimir Putin.
“The time has come to put an end to the Kremlin dictatorship,” a spokesman said. “Be brave and have no fear because we are coming home.”
Vyacheslav Gladkov, the governor of Belgorod, said that a Ukrainian “sabotage group” had entered the region from across the border.
In a statement on Telegram he wrote: “The armed forces of the Russian Federation, together with the border service, the National Guard and the FSB, are taking the necessary measures to eliminate the enemy.”
One video shared via the Telegram messaging app appeared to show a Russian helicopter dropping distraction flares over Kozinka as battle raged below.
Dmitry Peskov, the Kremlin spokesman, said Putin had been briefed on the incursion.
“We perfectly understand the point of such acts of sabotage – to divert attention from the Bakhmut front line,” he said.
“Work is underway to push out Ukrainian saboteurs from Russian territory and destroy the sabotage group. There are enough resources and manpower on the ground.”
Andriy Yusov, a spokesman for Ukraine’s military intelligence, insisted the incursion had not been carried out by personnel from the country’s armed forces.
“Russian nations, the [RFL and RDK] have claimed responsibility for those actions. I think we can only welcome those decisive steps by opposition-minded Russians who have taken up arms to fight the criminal regime of Vladimir Putin that has usurped power in Russia,” he said.