Ukrainian forces have attacked two “shadow fleet tankers” in waters at the entrance to the Russian Black Sea port of Novorossiysk, Ukraine's President Volodymyr Zelenskyy has said.
"These tankers had been actively used to transport oil, not anymore," Zelenskyy said on the Telegram messaging app on Sunday.
"Ukraine's long-range capabilities will continue to be developed comprehensively at sea, in the air, and on land."
Ukrainian drones also attacked Russia's Baltic Sea port of Primorsk, setting it on fire, local governor Alexander Drozdenko said on the Telegram messaging app.
He said more than 60 drones were downed overnight over Russia's northwestern Leningrad region.
There was no oil spill following the attack on Primorsk, a major oil exporting outlet, and the fire was extinguished, he added.
Russian drone strikes on Ukraine killed three people across the country, while Ukrainian attacks killed one near Moscow.
Russian attacks on Ukraine's southern Odessa region, home to key export terminals, killed two people, including a truck driver at a port, regional governor Oleg Kiper said on social media.
"Enemy drones hit three residential buildings, and two more were damaged. Facilities and equipment for the port infrastructure were also damaged," he said.
The emergency services posted photos of firefighters tackling a blaze after the attacks.
Russian strikes on the frontline region of Kherson, in southern Ukraine, also killed one person, officials there said.
Russia fired 268 drones and one ballistic missile in the overnight attack, Kiev's air force said.
Ukraine's army, meanwhile, launched at least 334 drones at Russia, Moscow's defence ministry said.
The northwestern Leningrad region was heavily targeted.
Oil export terminals there have been hit several times in recent weeks, knocking out billions of dollars worth of exports, according to Kiev.
