# Ukraine’s ‘Operation Vivaldi’ Reports Gains and Heavy Russian Losses in Northern Donetsk

*Tuesday, September 15, 2026 at 8:06 AM UTC — Hamer Intelligence Services Desk*

**Published**: 2026-09-15T08:06:52.925Z (2h ago)
**Category**: conflict | **Region**: Eastern Europe
**Importance**: 9/10
**Sources**: OSINT
**Permalink**: https://hamerintel.com/data/articles/17897.md
**Source**: https://hamerintel.com/summaries

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**Deck**: Ukraine’s 3rd Army Corps says Operation Vivaldi has cleared Russian infiltration across about 75 km² and liberated a further 10 km² in northern Donetsk region, including Serednie, while inflicting heavy losses on Russia’s 20th and 25th armies.

Ukraine is trying to turn a largely static front into a moving one again—and this time it has put a name on the effort.

The country’s 3rd Army Corps has officially announced Operation Vivaldi, saying Ukrainian forces have launched an offensive in the north of Donetsk region. In its first public summary, the corps reports eliminating Russian infiltration across roughly 75 square kilometers and liberating another 10 square kilometers of occupied territory, including the settlement of Serednie.

According to the corps, Ukrainian troops have cleared Novoselivka, Oleksandrivka, Yarova and areas around Korovyi Yar of Russian groups that had dug in or slipped across earlier lines. The 3rd Army Corps lists a wide mix of participating units, including the 60th and 66th mechanized brigades, the 125th brigade, elements of the 3rd assault brigade, a special unit from Ukraine’s military intelligence directorate and a mobile border guard detachment. That mix points to a coordinated push rather than a single isolated raid.

The corps claims that Russia’s 20th and 25th armies lost around 1,500 troops during the fighting. Those figures can’t be independently verified, and Moscow has not issued its own detailed account of losses in the area. The report nonetheless fits with the fact that these Russian formations have been heavily engaged on the eastern front for months.

For people living in this part of northern Donetsk, the operation means renewed shelling, more armored vehicles on the roads and the uncertain relief that comes when control changes hands. Places like Serednie and the surrounding villages are small, but each shift in the line affects who runs local roads, supply points and evacuation routes.

Militarily, gains measured in a few dozen square kilometers may look modest against the length of the front, but they carry weight. For Kyiv, showing it can still retake ground from entrenched Russian positions bolsters its argument to partners that military support does more than maintain a stalemate. For Moscow, being forced to contest or give up positions in what it had treated as a relatively stable sector risks pulling in reinforcements from other pressured fronts.

Operation Vivaldi is unfolding alongside a wider Ukrainian effort to stretch Russian logistics and industry. The General Staff has recently highlighted strikes on refineries, petrochemical plants, radars, naval bases and other targets up to 3,000 kilometers inside Russia. The idea is to combine local offensives like this one with long‑range attacks, making the front line more expensive to hold while the rear becomes less secure.

The core test for Kyiv now is whether it can consolidate these gains. Signs to watch include any attempt to push beyond Serednie toward larger hubs, evidence that Russia is diverting fresh battalions into northern Donetsk and changes in Ukrainian messaging if casualties or ammunition shortages start to bite. If Operation Vivaldi yields a more stable new line rather than a brief salient, it will influence how both sides plan for the coming months.