By Stefan Korshak

Copyright kyivpost

A Ukrainian counterattack in the northern Sumy sector captured a defensive line held by elite Russian “marines” capturing prisoners and putting survivors to flight, a Kyiv Post review of battle reports, geo-located content and official statements covering the weekend action found.

Elements of Ukraine’s 225th Assault Regiment attacking north from the villages of Kindrativka and Andriivka used artillery, mortars, drone strikes and armored infantry assaults to break positions held by Russia’s 810th Naval Infantry Brigade, video published by that unit and Ukraine’s General Staff showed.

The battalion-sized attack led by a picked strike group called Storm Group Morok also captured the villages of Novokonstantynkivka and Konstantynivka in fighting on Sunday and Monday, and pushed patrols to the Russo-Ukraine border just north of the latter village, some pro-Ukraine sources claimed.

In Armed Forces of Ukraine (AFU) practice a battalion usually numbers between 300 and 600 personnel.

The independent battle watch group DeepState on Wednesday reported that geo-location showed Russian forces were still present in strength in those two villages, with Ukrainian forces dominating open ground and threatening to cut Russian defenses off.

Russian milbloggers led by the Moscow-sponsored Dva Mayora (1.2M followers) confirmed on Wednesday fierce fighting was in progress in Sumy region with repeated Ukrainian assaults, but claimed Russian forces had repelled all attacks with “heavy losses” to Kyiv’s troops.

Russia’s Defense Ministry, in its Wednesday morning situation report, announced its forces in the Sumy-Andriivka sector had “inflicted a defeat” on two Ukrainian mechanized infantry brigades and a Ukrainian assault infantry brigade.

Kyiv Post was unable to find confirmation of the Kremlin claim, even among pro-Moscow milbloggers.

The major Russian propaganda outlet RIA Novosti on Monday identified the 225th Brigade as the attacking unit in the Kindrativka-Andriivka sector and told viewers the Ukrainian assaults “were completely liquidated,” but did not make publish evidence supporting the report.

Drone video published by the 225th Assault Regiment on Monday and geo-located to the Sumy region battle area told a different story, showing Russian infantry running from a wood line under mortar fire. Subsequent images showed Russian infantry troops attempting to swim a river and attacked by drones. A 225th statement alleged it was retreating Russian marines.

The mood of unit social media reviewed by Kyiv Post was jubilant with posters reporting a solid battlefield success with a fortification line and Russian prisoners of war captured, and minimal Ukrainian casualties.

The Telegram-based independent Russian military information channel Severniy Kanal (33,000 followers) reported on Wednesday Russian troops still held portions of Andriivka but they were “effectively surrounded.” In a Monday report that source identified Russia’s 30th Motor Rifle Brigade and the 177th and 810th Marine Infantry Brigades as the backbone of Kremlin defensive forces in the area.

Ukraine’s General Staff in a Wednesday situation update reported Ukrainian forces had posted gains in the northern Sumy sector and that combat was in progress.

On Wednesday, the General Staff published an interview with an alleged member of Russia’s 810th Naval Infantry. Per that account, his unit suffered 80 percent casualties from Ukrainian drones and artillery attacking his position for more than a week, and when Ukrainian assault troops entered his entrenchment he gave up.

Kyiv Post could not confirm the authenticity of the video, but the soldier’s account was consistent with statements made by other prisoners of war from that unit.

Russia in May launched a major cross-border offensive into Ukraine’s northern Sumy region, capturing close to three dozen villages and carving out a 10 kilometer x 30 kilometer salient in Ukrainian territory.

Following the weekend battles around Andriivka, Kyiv’s forces had freshly liberated a roughly 4 kilometer x 4 kilometer fraction of that lost ground.

The relatively modest Ukrainian counterattack success in the northern Sumy sector took place against the background of a more substantial Ukrainian counteroffensive victory in the eastern Pokrovsk sector.

Russian forces in August carved out a 15-kilometer deep salient in Ukrainian lines near the strategically-important eastern Pokrovsk, only to lose most of it in following weeks to counterattacking Ukrainian assault infantry and airborne assault infantry.

Ukrainian marine, airborne, and assault infantry units concentrated in the sector by AFU high command had by mid-September regained most of the lost ground, surrounded surviving Russian forces in at least two pockets near the town of Dobropillya, and taken close to one hundred Russian troops prisoner.

AFU Commander-in-Chief General Oleksandr Syrsky in a Wednesday statement published by his office said that Ukraine’s forces generally are standing on the defensive and counterattacking on opportunity.

He claimed that in the first eight and a half months of 2025, effective Ukrainian defensive tactics had “eliminated” more than 305,000 servicemembers of the Russian army, and destroyed or otherwise put out of action “almost” 30,000 combat vehicles, he said.

According to independent analysts, Russian forces – albeit at a snail’s pace and at the price of severe losses – have scored continuous marginal ground gains throughout the summer. Analysis published by the Washington-based Institute for the Study of War (ISW) in early September put total Russian ground gains from July 29 to Aug. 26, 2025 at around 466 square kilometers of Ukrainian territory, and from Aug. 19 to 26 about 124 square kilometers.

Syrsky, according to Ukrainian news reports in early September, sacked two Corps commanders, Volodymyr Silenko of the 17th Corps and Maksym Kituhin of the 20th Corps, for losing ground respectively to advancing Russian forces in the Zaporizhzhia and Dnipro sectors.

AFU leadership has not formally announced the firings, first reported by the Ukrainska Pravda news magazine on Monday. The article said Syrsky’s decision was “directly connected with the loss of positions in the corps’ areas of responsibility.”