Thousands of people have fled their homes in Russia’s Kursk region after about 300 Ukrainian soldiers crossed into the border region on Tuesday, according to a Russian Defense Ministry official.
According to Moscow, troops supported by 11 tanks and more than 20 armoured fighting vehicles crossed the border near the town of Sudza, about 10km (6 miles) from the front line, where fighting continued.
Fighting reportedly took place throughout Tuesday in several villages on Russian soil, followed by Ukrainian airstrikes that killed three civilians and continued into the night, Russian authorities said.
Kyiv officials have yet to comment on Russia’s claims.
Moscow said Ukrainian shelling along its border area had wounded 24 people, including six children.
On Wednesday, the Russian Defense Ministry claimed it had prevented Ukrainian troops from advancing “deep into Russian territory” in the Kursk region, destroying several Ukrainian drones overnight.
However, several air warnings continued to be issued in Kursk, local authorities urged residents to limit their movements and all public events were canceled.
Footage posted online and verified by the BBC showed fighter jets flying low over the area on Tuesday, with smoke billowing from the ground.
Regional acting governor Alexei Smirnov said he had briefed Russian President Vladimir Putin on the situation and that it was now under control.
Mr Smirnov also added that thousands of people had been evacuated from the affected areas and that doctors had been sent from Moscow and St Petersburg to provide assistance.
The Kiev side has not yet commented on any reports about the events in Kursk.
Vladislav Seleznov, a colonel in the Ukrainian military, told the main Nextar channel that the offensive was “preventive” and that some 75,000 Russian troops were still massing near the border.
Following Russia’s major border incursion into the northeastern Kharkiv region in May, there were concerns that Moscow would attempt a similar incursion into the Sumy region to the north.
Those ambitions have likely been thwarted, as Ukraine appears to have seized several settlements and highways in different directions.
But some military analysts question the wisdom of such cross-border raids, given that the Ukrainian military is already overstretched and undermanned.
This is not the first time that Ukraine-based fighters have invaded Russia. Some anti-Kremlin Russian groups launched airstrikes last year, but were repelled.
In March, troops again advanced into the Belgorod and Kursk regions, clashing with Russian security forces.
