# Russian military activity in the Baltic Sea

> Live situation record from CLSTR: https://clstr.news/situations/russian-military-activity-in-the-baltic-sea
> Updated: 2026-08-20T10:47:20.000Z. Sources: 12. Developments: 2.

Russia has increased its military presence in the Baltic Sea, deploying advanced warships including the destroyer Admiral Levchenko and the frigate Admiral Kasatonov. The Kasatonov, commissioned in 2020, is equipped with Kalibr and nuclear-capable Zircon hypersonic missiles, which place several NATO nations—including Germany, Denmark, Sweden, and Poland—within strike range.

Recent sightings have placed the Admiral Kasatonov near the German island of Fehmarn. This movement follows threats from Vladimir Putin regarding retaliation against British and EU vessels involved in inspecting the Russian ‘shadow fleet’ of tankers used to bypass sanctions. Concurrently, Deputy Security Council Chief Dmitry Medvedev has asserted Russia’s right to attack merchant ships belonging to hostile states.

These maritime movements coincide with intelligence warnings from the CIA regarding potential Russian strikes against NATO members to test alliance resolve. Reports also indicate Russia is expanding military bases near the borders of Ukraine and Belarus to facilitate the launch of jet drones capable of penetrating NATO territory.

## Claims

- The Russian frigate Admiral Kasatonov was spotted near the German island of Fehmarn in the Baltic Sea. (corroborated by 5 sources)
- The Admiral Kasatonov is a 2020-built vessel equipped with nuclear-capable Zircon hypersonic missiles. (corroborated by 5 sources)
- Vladimir Putin threatened retaliation against British and EU ships following inspections of the Russian shadow fleet. (corroborated by 5 sources)
- US intelligence reports warn that Russia could launch an attack on the Western alliance within weeks to test its resolve. (corroborated by 5 sources)
- Russia is reportedly building secret bases near the Ukrainian border to produce advanced attack drones. (corroborated by 2 sources)
- The Zircon hypersonic missiles have a range of approximately 1,000 kilometers. (single source)
- Dmitry Medvedev stated that Russia has the right to attack any merchant ship belonging to a hostile state. (single source)

## Timeline

### 2026-08-20: Russian frigate Admiral Kasatonov spotted near German island Fehmarn

The Russian frigate Admiral Kasatonov, armed with nuclear-capable Zircon hypersonic missiles, was spotted near Germany's Fehmarn island, escalating tensions in the Baltic Sea.

8 sources. https://clstr.news/cluster/russian-frigate-admiral-kasatonov-spotted-near-german-island-fehmarn

### 2026-08-17: Russia deploys advanced warships to Baltic Sea amid NATO security warnings

Russia has deployed advanced warships, including the Admiral Kasatonov, to the Baltic Sea near Germany, amid CIA warnings that Moscow may attack a NATO member within weeks.

4 sources. https://clstr.news/cluster/russia-expands-baltic-sea-naval-presence-with-advanced-frigate

---
Cite as: Russian military activity in the Baltic Sea. CLSTR, https://clstr.news/situations/russian-military-activity-in-the-baltic-sea