Russia appears to have launched initial major counterattack against Ukraine in Kursk

Russia appears to have launched its first major counterattack to drive Ukrainian forces out of Russia's Kursk region more than a month after Ukraine began its surprise offensive, according to Russian and Ukrainian sources as well as independent military analysts.

Russian forces appeared already to have some success on Tuesday -- retaking some territory and driving a wedge into Ukrainian lines in Kursk, analysts said.

Videos posted by pro-Russian military bloggers and geolocated by ABC News showed a large Russian armored column attacking toward the village of Snagost. Another video appears to show Ukrainian troops taken prisoner.

The Russian counterattack is focused on the western flank of Ukraine's incursion into Kursk that seized hundreds of square kilometers since it began on Aug. 6.

John Helin -- a researcher at the Blackbird Group, which conducts open-source military analysis -- wrote on X that Russian troops had launched a push from the west and north, driving a wedge behind Ukrainian troops toward Snagost. Russian military bloggers claim Russian forces are now attacking the village of Obukhov, which would mean Russian troops could have advanced more than 6 miles on Tuesday, Helin wrote in an article for the Finnish newspaper, Helsingin Sanomat.

A prominent pro-Ukrainian military blogger, Serhiy Sternenko, confirmed Russia has launched a major counterattack and that the situation is dangerous for Ukraine.

"The situation can develop into a poorly controlled crisis," Sternenko wrote on Telegram, saying Ukrainian forces lack adequate coordination in the area and are disorganized.

Military analysts and Ukrainian commentators said Russia's attack was predictable.

"I won't dramatize about the Kursk region, war is war, a fully expected response from the enemy," Stanislav Osman, a volunteer soldier with the 24th "Aidar" Assault Battalion, wrote on his Telegram account. But he said Ukrainian commanders had ignored some warnings from Ukrainian front-line troops in the area.

Ukraine succeeded in seizing hundreds of square miles and dozens of villages inside the Kursk region in the early days of its surprise offensive. Russia has struggled to respond. Ukraine has barely advanced since the first two weeks, although it has kept Russian forces on the defensive. Tuesday's counterattack suggested Russia is now finally seeking to turn the tables and begin trying to push Ukraine back.

Ukraine's incursion into Kursk has been viewed as a high-risk gamble by most independent military experts. Although it has succeeded in shifting the narrative in the war, analysts have warned Ukraine still risks suffering dangerous losses as it tries to hold onto territory in Kursk.

At the same time, Russian forces have made more rapid advances in eastern Ukraine since the Kursk incursion, appearing to take advantage of Ukraine diverting troops and ammunition. Russian forces have advanced toward the city of Pokrovsk, a key logistical hub, and stretched Ukrainian lines more broadly in southeast Donbas. Though Russia's rate of advance has reportedly slowed in the past week.