Finnish officials confirmed that a Russian warship was attacked in the Gulf of Finland on Wednesday, though the military has released few details about the location, timing, or how the strike was detected.

A spokesperson said the Finnish Defence Forces "detected… a strike on a Russian warship in the Gulf of Finland area and has monitored the development of the situation," adding that Finland is not under any immediate military threat.

Finland's Foreign Minister Elina Valtonen insisted the situation in the Baltic Sea remained stable and safe, with no threat of any kind to marine traffic. Finnish officials described the incident as a direct result of Russia's continued full-scale war.

Ukraine's SBU security service said it targeted the ship Naro-Fominsk, a Buyan-M class small corvette that the SBU said carried Kalibr and Oniks cruise missiles, as part of a broader drone operation against Russia's Ust-Luga oil export depot on the Baltic coast.

The SBU said it detected the ship in Russia's Leningrad region on the night of Nov. 11. According to the BBC, there were also unconfirmed reports of Russian combat helicopters being destroyed.

The strike is thought to be the first time Ukrainian drones have attacked a Russian ship in a Baltic area open to civilian shipping, raising questions about whether Ukraine could expand its strikes.

Russian and Ukrainian vessels have been repeatedly targeted in the Black Sea since Russia's full-scale invasion began in February 2022, but the Baltic Sea fleet had been untouched up to this point.

"The Baltic Sea fleet has been untouched up to this point but there seemingly was a window of opportunity for Ukraine and they understandably tried to use it," said military analyst Emil Kastehelmi, co-founder of the Black Bird monitoring group, who told the BBC he did not consider the strike a serious escalation despite its unprecedented nature.

Estonia's defence minister Martin Herem told public broadcaster ERR the ship was hit at about 05:30 (03:30 GMT), saying: "We know that smoke came from the ship afterwards. The ship itself went back towards St Petersburg."

The warship strike came amid a wider overnight drone operation against the Ust-Luga terminal, a major Baltic export outlet for commodities such as oil and grain.

Several storage tanks there are thought to have been hit overnight on Wednesday, and fires at the port were visible over the border in Estonia.

Herem said Ukrainian drones attacked the Ust-Luga region from midnight until about 06:00, mostly flying close to the Estonian border but still in Russian airspace, though one drone briefly entered Estonian airspace from Latvia before heading towards Russia.

NATO aircraft based in the Baltic states were in the air, but Herem said it had not been considered safe for them to destroy the drones. Estonia, Latvia and Lithuania issued shelter warnings and NATO scrambled warplanes.

Russia said it had intercepted at least 146 Ukrainian drones in the Leningrad region, per Al Jazeera.

Moscow alleged that Kyiv had used the airspace of the Baltic states to attack Russia, but Ukrainian foreign ministry spokesman Heorhiy Tykhyy called those allegations "baseless" late on Wednesday, while acknowledging "incidents might occur when Russia diverts drones from its airspace using electronic warfare."

The strike also raises stakes for civilian traffic: Finnish defence officials are understood to have stressed to Kyiv that the Gulf is a narrow waterway used by oil tankers and civilian vessels and is also home to subsea data cables.

Some Ukrainian drones have strayed into the airspace of Finland and the Baltic region, fueling fears that the war is spilling over into NATO countries bordering Russia and Belarus.

The Naro-Fominsk is believed to have headed back to port in St Petersburg after the attack, and the extent of casualties or damage remains unclear, with Moscow rarely giving such details.

Analysts suggest the strike exploited a rare window of opportunity against a fleet previously untouched in the Baltic, and the question now is whether Ukraine will expand its naval drone campaign beyond the Black Sea.

The attack coincided with renewed US shuttle diplomacy: envoys Steve Witkoff and Jared Kushner met President Putin in Moscow, then flew to Dublin to meet President Zelenskyy, producing no major breakthrough aside from an agreement on a large prisoner exchange that TASS reported should happen in two to three weeks.

Kushner said the US is working toward what would be the largest prisoner exchange of the war, and plans for another round of talks with Europe promised a seat at the table were announced.