Ukraine has launched a major attack with its troops into Russia, in what appears to be its biggest and most serious incursion into the country since Moscow's full-scale invasion began in February 2022.
A Ukrainian force numbering in the hundreds backed with armored vehicles advanced on Tuesday across the border into Russia's Kursk region, according to official and unofficial Russian sources, although exact details remain deeply unclear.
The Ukrainian troops appeared to have captured a number of settlements in the border area around the village of Sudzha, advancing perhaps as much as 15 km inside Russia, according to pro-Kremlin Russian military bloggers, with heavy fighting reported to be continuing for a second day.
The Ukrainian incursion prompted Russian President Vladimir Putin to hold urgent meetings on Wednesday with his government and defense leadership, while local authorities said thousands of Russian civilians were being evacuated away from the fighting.
The Russian Telegram account VChK-OGPU, that is linked to the Wagner mercenary group, on Wednesday claimed a column of Ukrainian troops had passed through the village of Lyubimovka, roughly 6 miles inside the border and that they appeared to be moving towards another village Korenovo.
Ukrainian troops also reportedly entered the border town of Sudzha, according to Russian military blog accounts and videos circulating online geolocated by ABC News. Sudzha is home to a key pipeline hub for supplying gas to Europe. Another prominent military blog account close to Russia's defense ministry, Rybar, reported the situation for Russian forces had continued to deteriorate Wednesday and that earlier Ukrainian troops had entered at least 11 settlements since Tuesday, though not seizing most.
Russia's defense ministry initially claimed to have rebuffed the Ukrainian attack and forced them to retreat. The head of Russia's General Staff, Gen. Valeriy Gerasimov, on Wednesday briefed Putin that more than 1,000 Ukrainian troops had crossed the border and claimed that hundreds had been killed and wounded. But it was clear on Wednesday that intense fighting was continuing, as Russian officials announced further evacuations of civilians from the region. At least 31 civilians have been injured by shelling, according to local officials in Kursk.
Videos posted online by civilians, as well as alarmed posts by the Russian military bloggers, suggested a chaotic situation in the border area, with Russian forces not in control. Videos posted by Ukrainian accounts online and geolocated by ABC News appeared to show dozens of Russian soldiers taken prisoner lying down on a road on the outskirts of Sudzha.
Rybar, the account close to Russia's defense ministry, claimed at least 2,000 Ukrainian troops were massed over the border and that Ukrainian engineering units were moving in to erect fortifications.
Though the picture remained wrapped in uncertainty Wednesday, it was clear the Ukrainian attack was the largest it has mounted into Russia. Ukraine has previously launched smaller raids using Russian groups opposed to the Kremlin and controlled by Ukrainian intelligence, entering border villages and then retreating. This is the first time, Ukrainian military units have entered Russia in such numbers.
Ukrainian officials have been silent on the operation publicly, declining to confirm Ukraine's involvement as in previous incursions while they were ongoing.
Multiple theories have appeared for Ukraine's possible goal with the offensive, with most analysts suggesting it could be an attempt to force Russia to divert forces away from elsewhere in Ukraine at a time when Ukrainian forces are under intense pressure in parts of the Donbas region. Some Ukrainian analysts have also indicated it could be an attempt to pre-empt a planned Russian offensive into the neighboring Ukrainian region of Sumy.
Some have also speculated Ukraine could be seeking to seize territory to give it leverage in potential peace negotiations to trade for Ukrainian occupied territory. Russian military bloggers have expressed alarm that Ukraine could even be seeking to seize the Kursk Nuclear Power Station that lies about 35 miles from the border. That appears unrealistic for such a small force to capture, although Russia's National Guard on Wednesday announced it was reinforcing security at the plant.
Others have speculated Ukraine could be attempting to capture or damage the Sudzha gas pipeline hub, to disrupt Russian supplies to Europe.
Some Ukrainian and independent military analysts have questioned the wisdom of such a risky operation at a time when Ukraine is suffering from intense troop shortages and Russian forces have been advancing towards the key strategic city of Pokrovsk in Donbas.
Editor's note: This story corrected that the figures released from local officials in Kursk were of those injured in shelling.