Ukraine has struck Russia's largest oil terminal on the Baltic Sea during one of its biggest overnight drone attacks in months.

The aerial assault targeted the Primorsk oil port in the Leningrad region, the final station of the Baltic Pipeline System and a crucial hub for Russia's maritime exports, Ukraine's security services told multiple outlets.

More than half of the 221 drones sent to Russian territory were intercepted over the Bryansk and Smolensk regions, where Lukoil facilities were also reportedly targeted, the Russian defense ministry said. Two civilians were killed in Ukraine's Sumy region when a Russian glide bomb struck a village near the border.

Authorities in the Leningrad region stated that 28 drones were brought down and that a fire had broken out at a vessel and a pumping station in Primorsk, although the blaze was extinguished without casualties or leaks. The port is also central to Russia's so-called 'shadow fleet' of aging tankers used to skirt international sanctions.

The Ukrainian security services indicated that drone strikes also hit several pumping stations feeding the Ust-Luga terminal, near the border with Estonia. In a separate incident, Russian state energy firm Rosatom reported a drone attack on a power unit at its Smolensk Nuclear Power Plant, near the Belarussian border.

Russian officials claimed drones were intercepted across at least nine other regions, with debris reported but no casualties confirmed. In Bryansk, a drone hit a bus, injuring seven, including five civilians and two military personnel, according to regional authorities.

This aerial assault marks one of the most significant for the Leningrad region since the full-scale invasion of Ukraine began. Operations at St Petersburg's Pulkovo airport were temporarily suspended, adding to the disruption.

Cross-border drone raids have become increasingly prominent in the ongoing conflict. Recent months have seen Ukraine extend its strikes deeper into Russian territory, targeting critical infrastructure like refineries and fuel depots in an effort to reduce Russia's oil supply and increase operational costs.