Overnight into 6 June, Ukraine's Unmanned Systems Forces sent more than 400 drones deep into Russia and set fire to the missile corvette Boikyi at Kronstadt, the Baltic Fleet's home base outside St Petersburg1. It was the first confirmed Ukrainian strike on a Russian warship in the Baltic Sea, around 1,000km from the border. The same wave hit the Petergofskaya oil depot, the Neste terminal at Lomonosov, and a naval arsenal at Bolshaya Izhora. Moscow has not disputed the strike, only its scale.
The strikes landed during the St Petersburg International Economic Forum, the event Putin uses to court foreign investors and project stability. Brovdi, the drone-forces commander, said his units tracked down and set fire to the corvette, the same vessel that had escorted Russia's sanctioned shadow-fleet tankers through the English Channel in 2025. Hitting the flagship economic forum with a naval fire punctures the calm Putin was selling.
Twelve months earlier, Ukraine's Operation Spiderweb of 1 June 2025 destroyed Russian strategic bombers on the ground; the reach has only lengthened since. Kronstadt had been treated by Moscow as an untouchable rear-area base; it now sits inside Ukrainian range, the same assumption of a secure rear that its declining oil revenue had already begun to test. No Russian rear area now reads as safe.
