Russian troops are falling back in Sumy Oblast in northern Ukraine.

That’s not surprising. The Kremlin has pulled no fewer than five marine and airborne brigades, regiments and divisions from Sumy and redirected them south to Donetsk Oblast, where a pair of Russian field armies are struggling to hold back a Ukrainian counterattack.

Both sides in Russia’s 43-month wider war on Ukraine have shifted troops from Sumy to Donetsk as the battle for the fortress city of Pokrovsk intensifies. But it’s evident the Russians have weakened their forces in Sumy more than the Ukrainians have.

In recent days, Ukrainian troops have ejected the Russians from the area around the villages of Kostiantynivka and Novokostiantynivka in Sumy just a few hundred meters from the border with Russia, analysis group Deep State reported Sunday.

“There are achievements in the Sumy region,” Ukrainian Pres. Volodymyr Zelensky announced on Sept. 12.

It seems the 810th Naval Infantry Brigade is the main Russian formation in the vicinity of Kostiantynivka and Novokostiantynivka. It’s the last large marine unit left in Sumy after the Kremlin concentrated five marine regiments and brigades east of Pokrovsk in recent weeks.

Pokrovsk is one of the last major Ukrainian strongholds between hundreds of thousands of Russian troops and the main Kramatorsk-Sloviansk urban center in western Donetsk. If Pokrovsk falls, all of Donetsk may fall.

Donetsk is the priority. And the Kremlin seems to be willing to risk its gains in Sumy to make further gains in Donetsk. In addition to moving the marines to the east at the expense of the north, Russian commanders have shifted existing field armies in the sector surrounding Pokrovsk.

East of Pokrovsk, three Russian field armies and corps—the 8th and 51st Combined Arms Armies and the 68th Army Corps—face around nine Ukrainian regiments and brigades plus a few separate battalions, some of them under the command of the new 1st Azov Corps.

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Russia saved armor all year for this moment—150,000 troops close in on Pokrovsk

Russian horde

Counting the newly arrived marines, there may be around 80,000 Russians and perhaps half as many Ukrainians along a stretch of the front line that’s no longer than 25 km.

Ukrainian forces may have an advantage in drones, however. Russian marine commanders are reluctant to deploy their armored vehicles toward Pokrovsk “due to the enormous amount of [Ukrainian] UAVs in the air, Ukrainian drone operator Kriegsforscher explained.

The Russians are still reeling from the 1st Azov Corps’ recent counterattack against a Russian motor rifle brigade that infiltrated under-manned Ukrainian lines northeast of Pokrovsk last month; even with all those reinforcements, they’ve yet to regain the momentum in the sector.

And that middle performance so far may be costing them in Sumy as the Ukrainians take advantage of new gaps in Russian lines.

This was a predictable outcome. In robbing Sumy to reinforce Donetsk, the Kremlin gambled the Ukrainians had finally exhausted their reserves and could no longer respond in kind in Donetsk—or exploit Russian weakness in Sumy.

The gamble hasn’t paid off—at least not yet. At least one observer expected this would happen. The Russians “actually thought Ukraine was out of infantry,” American analyst Andrew Perpetua mused.

While it’s true Ukrainian brigades are struggling with a shortage of trained infantry, there’s a big difference between Ukraine have too few trigger-pullers to comfortably perform every possible mission … and having so few that it’s impossible to respond to large-scale Russian moves like we’re seeing in Donetsk and Sumy.

According to Perpetua, Ukrainian commanders had made the deliberate decision to leave some trenches empty—potentially including some around Pokrovsk—in order to buy time for certain brigades, such as the 95th Air Assault Brigade, to rebuild.

“It was a sacrifice,” Perpetua said. “Sacrifice ground for time while refitting and then you can attack later.”

It’s possible these rebuilt brigades are the ones giving the Russians so much trouble now—counterattacking in Donetsk and Sumy, and pushing back the Russians in the latter oblast. The 95th Air Assault Brigade, it’s worth noting, is on the front line in Sumy.

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Russian marines rushed to save the Pokrovsk offensive—HIMARS had other ideas

Russian forces attacked Zaporizhzhia district overnight against 15 September, causing fires in private houses, according to regional officials. No casualties have been reported at this time.

The assault began around 2:28 am when explosions were heard in Zaporizhzhia city. “Preliminarily, no casualties,” Zaporizhzhia Oblast Governor Ivan Fedorov said.

Russian troops struck the district three times, Fedorov confirmed at 4:07 am.

The strikes damaged infrastructure across multiple communities. Power supply was cut in one of the communities, while private houses caught fire in Zaporizhzhia district proper.

Russian forces also targeted the suburbs of Zaporizhzhia, damaging a house in a garden cooperative area. The attack left no injuries or fatalities, according to the regional administration.

Separately, Russian troops conducted at least four strikes against Kushugum community. The attacks damaged roofs, walls, and shattered windows in the settlement, as shown by the regional military administration.

The Zaporizhzhia attack was part of a broader Russian offensive overnight. From 7:00 PM on 14 September, Russian forces launched three S-300 surface-to-air missiles from Kursk and Belgorod oblasts and 84 strike drones including Shahed, Gerbera, and other types from six directions: Kursk, Bryansk, Orel, Millerovo, and Primorsko-Akhtarsk. Approximately 50 of the drones were Shaheds, according to Ukrainian military reports.

The overnight assault follows a pattern of Russian attacks on civilian infrastructure on 14 September. Russian forces struck an agricultural enterprise in Boromlyanska community of Okhtyrka district in Sumy region, injuring 12 people involved in harvest collection. The attack used two missiles and damaged approximately 30 units of agricultural equipment, according to Sumy region prosecutor’s office.

Eleven men were hospitalized from the Sumy attack, with one in serious condition, confirmed Oleh Hryhorov, oblast governor.

Russian military leadership denies targeting civilian infrastructure during the full-scale war, despite documented strikes on hospitals, schools, kindergartens, energy facilities, and water supply systems. Ukrainian authorities and international organizations classify these attacks as war crimes committed by the Russian Federation.

Ukrainian President Volodymyr Zelenskyy said on Telegram that Russian attempts to advance in the Sumy oblast have been fully repelled by Ukrainian forces.

Russian forces have been trying to break through Ukraine’s Sumy Oblast for months, but made little progress. 

Sumy Oblast is in northeastern Ukraine, bordering Russia’s Bryansk, Kursk, and Belgorod regions. The city of Sumy lies about 15 miles from the Russian border, making the area a frequent target for Russian drones, missiles, and guided bombs.

Zelenskyy added that while fighting continues along the border, Russian units have lost their offensive capability due to heavy losses.

Last month, Ukrainian Armed Forces Commander-in-Chief General Oleksandr Syrskyi reported that Russian forces had been defeated in Sumy Oblast and lost several settlements. He added that Russia is now redeploying troops to other fronts, including Zaporizhzhia.

Although Russian forces initially captured several villages this year, they were ultimately halted by Ukrainian defenses.

Ukrainian civilians continued to face Russia’s daily drone, missile, and artillery assaults, with Moscow strikes killing at least 6 civilians and injuring 19 across multiple oblasts yesterday and last night.

Last night, Russia launched a smaller wave of long-range explosive drones than usual—only three dozens instead of usual hundreds, but still inflicted deadly strikes. Russian Shahed drones, FPVs, missiles, and other weapons hurt Ukrainian civilians across Sumy, Zaporizhzhia, Kharkiv, Donetsk, Kherson, and Dnipropetrovsk oblasts.

Ukraine’s Air Force says it has intercepted or jammed most long-range drones. Despite that, multiple strikes landed, including one in Sumy that killed a man trapped under rubble after Russia launched a second drone before rescuers could reach him.

Ukraine downs 33 drones—but six hit civilian targets

Ukraine’s Air Force reported on 12 September that Russia launched 40 strike drones, including Shahed explosive drones, Gerbera decoys, and others, from Kursk, Millerovo, and Primorsko-Akhtarsk. Over 20 of them were Shaheds, capable of carrying up to 90 kg of explosives. The attack began at 22:00 on 11 September and continued overnight. Air defense forces, mobile units, electronic warfare systems, and drone systems responded.

Sumy: Guard killed under rubble, teenagers injured, rescue blocked

On the morning of 12 September, Sumy experienced multiple explosions. Acting Mayor Artem Kobzar confirmed that two of them were drone strikes on a non-residential building. Suspilne noted the facility was a car service station. The attack targeted Sumy’s industrial area in Zarichnyi district, damaging infrastructure, transport, and multiple non-residential buildings.

According to the head of the oblast, Oleh Hryhorov, a 65-year-old security guard initially survived the first hit and contacted others. But after a second Russian drone struck, contact was lost. His body was later found beneath the debris.

Hryhorov said emergency services could not immediately conduct rescue and cleanup due to a Russian ZALA drone hovering above the area, blocking access to the site. The ZALAs are Russian reconnaissance drones, adjusting missile and drone strikes.

Elsewhere in Sumy oblast, in Velykopysarivska hromada, a Russian FPV drone hit a field road, injuring two 16-year-old teenagers who were riding a motorcycle.

Also in Sumy Raion, on the evening of 11 September, a Russian FPV drone struck a civilian car, injuring a 19-year-old girl, who was hospitalized.

On the morning of 12 September, Russia launched a missile strike on the Bytytsia rural community, part of the Sumy hromada, killing an unspecified number of people.

Yesterday’s attacks also targeted multiple civilian buildings. On 11 September, Russia damaged a hospital, school, vocational college, and homes in Sumy. Later, a Russian drone struck the Voskresenskyi Cathedral, breaking windows and damaging the structure. Earlier that morning, a Molniya drone hit a household on Kulykivska Street.

Local authorities report: Russia targets civilians across Ukraine

• Zaporizhzhia Oblast: In Primorske, a man died after a Russian drone strike on 11 September. The following day, a Russian airstrike hit Uspenivka, killing another man.
• Kharkiv Oblast: In Kupiansk district, Russian forces attacked Kivsharivka with artillery, injuring a paramedic and a medical technician when their ambulance came under fire. In Osynove, an FPV drone hit a police vehicle, injuring five officers. In Hrushivka, a Russian airstrike injured three civilians.
• Donetsk Oblast: Russian aviation struck Kostyantynivka with high-explosive bombs. A resident was pulled from the rubble alive, while another died, with their body still under debris.
• Kherson Oblast: Russian shelling injured a man in Kherson, a woman in Bilozerka, and a man in Mykilske. All were hospitalized, and one of them is in serious condition.
• Dnipropetrovsk Oblast: Russia attacked Nikopol and Synelnykove districts, injuring two women. Fires broke out, including in residential buildings.