Ukrainian forces on Sunday took down a logistically critical road bridge in Russia’s Kursk region, leaving Russian troops and civilians inside a strip of territory about the size of Luxembourg effectively cut off from escape or reinforcements.

Russian milbloggers and Ukrainian media agreed the span within the village of Karyzh was now unusable and Russian authorities in the region warned civilians that travel south across the river had become impossible. It was not clear what was used to disable the bridge.

Armed Forces of Ukraine (AFU) units have, since Kyiv’s Aug. 6 incursion into Russia’s Kursk region, employed special forces demolition teams, long-range guided missiles and air strikes to attack Russian road and transportation infrastructure. A tree-lined, waterway meandering through low-lying terrain, the Seym river and the ground area around it is impassable to vehicles, aside from where it is bridged.

An Aug. 16 strike blasted a two-meter-wide hole in a bridge some 5.5 kilometers (3.5 miles) to the east of Karyzh, near the village of Zhvannoe, making its use by vehicles impossible. A Ukrainian Air Force spokesperson said the precise hit was achieved using an air-dropped guided bomb. Geolocation research confirmed the location of the images to be Zhvannoe and the Seym River.

Screen grab of Ukraine Air Force drone video published on Sunday. Air Force spokesman Mykola Oleshchuk said the images showed a bomb hitting a critical road bridge in Russia. Kyiv Post researchers geolocated the images to a bridge crossing the Seym River to the north of the village of Zhdannoe.

AFU long-range artillery units used US-made Guided Multiple Launch Rocket Systems (GMLRS) to pound a third bridge across the river near the village of Glushkovo, some 8 kilometers (5 miles) east of Zhvannoe from Aug. 12 to 15. The strikes punched at least four large holes through the bridge’s reinforced concrete. An air-dropped guided bomb finally knocked the bridge down on Aug. 16, the Ukrainian air force spokesperson said.

Satellite and drone video images reviewed by Kyiv Post and geolocated to Glushkovo showed the north end of the bridge to be demolished. By Monday morning Ukrainian media and Russian milbloggers were reporting the destruction of the three bridges had left some 80 Russian villages in territory bordering Ukraine without road access to points north and east. Russian civilians and troops were attempting to evacuate to safety by small boats, the UNIAN news agency reported.

July reports and satellite imagery indicated that Russian forces had built a pontoon bridge across the Seym three kilometers (two miles) east of Glushkovo. On Monday it was not clear whether that bridge was still intact, but sources agreed it had been attacked by Ukrainian forces.

Since its offensive into Russia kicked off on Aug. 6 Ukraine had, occupied some 1,150 square kilometers of Russian territory according to an AFU statement on Friday. That figure is expected to have grown because Ukrainian troops were still advancing against limited resistance over the weekend.

Should Ukrainian forces gain control of the section of Kursk region now cut off from the rest of Russia by past AFU advances and the three recently destroyed bridges, the area of the Russian Federation now under control of Kyiv’s troops would have almost doubled in size. It was not clear how many Russian troops and military equipment, if any, were still in the isolated territory.

Photograph published by the pro-Russia milblogger Voenniy Osvedomitel’ showing a dropped span
of a  bridge across the Kursk region Seym River near the village Karyzh following a Ukrainian air strike.

According to Russian civilian reports, Russian troops abandoned the town of Tetkino, near the Ukrainian border and deep inside the now-isolated part of the Kursk region, on Saturday.

According to members of a Ukrainian mechanized infantry interviewed by a Kyiv Post reporter in the Russian town of Sudzha on Sunday, combat was continuing to the west of the town of Korenevo and at points some 20 to 40 kilometers (12 to 25 miles) north of the Ukrainian border, as well as to the east of Sudzha.

Kyiv Post image showing the trace of the Seym River in the southwest of Russia’s Kursk region. Three road bridges connect this 20 x 60 km. section of Russian territory to points north. Ukrainian long-range fires destroyed the last bridge standing in this portion of the Seym, in the vicinity of the village Karyzh  (left, circled), on Sunday afternoon.

AFU service personnel said overall Russian resistance in the Kursk region still appeared to be limited and disorganized. An AFU battalion commander said that in two weeks of combat his formation had yet to encounter any well-organized Russian defense.

Military analyst Donald Hill in an Aug. 19 weekly report identified the villages of Kremyanoe, Zhuravli, Novosyolovka, Pogrebki, Novosotnitskii, Osipova Luka, Belitsa, and Martynovka as current or recent fighting flashpoints across the Kursk sector, with Russian counterattacks are focusing on the eastern side of the Ukrainian salient, he said.

Russia’s national secret service (FSB) ordered the evacuation of civilians of the Rylsk and Lgov districts, to the north of that contact line on Sunday. At least 120,000 Russian civilians had fled the Kursk region and authorities were evacuating around 60,000 more, Hill wrote.

Ukrainian UAV teams had positioned a strong FPV presence along the E38 highway, a key logistics artery connecting the frontline towns Rylsk and Lgov with the regional center of Kursk over the weekend. Russian milbloggers said the road had become an “FPV kill zone.”

Map published by the pro-Kremlin information platform Agenstvo showing location of cut bridges over the Seym River and an isolated territory still controlled by Russian forces some 700 square kilometers in size.

Kyiv Post’s open-source research pinpointed at least six AFU mobile drone units operating in the Kursk region, among them elements of the Ptakhy Madyara regiment and the 501st Marine Battalion.

Russian prisoners of war recently captured by Ukrainian troops have told of facing massed artillery and drone swarms initiated by Kyiv’s forces.

A Russian prisoner of war, Private Aleksandr Belyaev, a communications operator in Russia’s 17th Motor Rifle Battalion, told Ukrainian military correspondent Yuriy Butusov that his unit had come under rocket artillery bombardments that killed his commander.  He said that Ukrainian strikes appeared targeted on Russian headquarters and commanders.

Russian army junior officers and NCOs stationed in forward positions abandoned their subordinates at the start of Ukrainian attacks, with morale among the rank and file in his unit poor, Belyaev said.