Kyiv's troops have in recent weeks stepped up attacks on Russian oil depots and refineries - key sources of revenue for Moscow's war budget - sometimes targeting sites thousands of kilometres from Ukraine's borders.
In the Leningrad region, which surrounds St Petersburg and borders Finland, Governor Alexander Drozdenko said a fire had been extinguished at the Vysotsk port, which houses a terminal operated by Lukoil handling exports of fuel oil, naphtha, diesel and vacuum gas oil.
In a statement on the Telegram messaging app acknowledging the port attack, Ukraine's drone forces commander, Robert Brovdi, said Ukrainian forces also attacked oil refineries in the cities of Novokuibyshevsk and Syzran in the Samara region.
Both sites have been repeatedly struck in the course of Russia's war in Ukraine.
"Make Russian Oil Great Again," he wrote sarcastically.
Brovdi also criticised the US decision to renew a waiver allowing countries to buy sanctioned Russian oil at sea.
Vyacheslav Fedorishchev, the Samara region governor, said industrial targets came under strike. He did not name the facilities.
According to Brovdi, a series of recent strikes on Russia's oil logistics at Primorsk, Ust-Luga, Sheskharis, Tuapse reduced total daily oil shipments by about 880,000 barrels. Reuters could not immediately verify the figure.
An oil depot in Russian-occupied Sevastopol in Crimea also came under attack on Saturday, Brovdi said.
Separately, authorities in the southern Krasnodar region said on Saturday that a fire at an oil depot in Tikhoretsk, and another at an oil terminal at the Black Sea port of Tuapse, which had burned since Thursday, had been extinguished.
Both fires, authorities have said, were caused by Ukrainian drone strikes.
The strikes come as Ukraine's President Volodymyr Zelenskiy said he believed Russia was making preparations to once again try to involve its ally Belarus in the four-year-old war.
Zelenskiy said Ukrainian intelligence indicated Belarus had begun expanding roads and building artillery positions in areas near Ukraine's border.
"We believe that Russia will once again try to involve Belarus in its war," Zelenskiy said on social media.
He did not provide evidence for the construction activities in Belarus.
In February 2022, when Russia launched its full-scale invasion of Ukraine, it also entered Ukrainian territory from Belarus.
Zelenskiy said on Friday that Ukraine had issued instructions to warn the Belarusian leadership of "Ukraine's readiness to defend its land and independence".
He also said Belarus's government should take note of what happened to Venezuela's leader.
"The nature and the consequences of the most recent events in Venezuela should prevent Belarus's leadership from making mistakes," Zelenskiy said.
In January the US military captured Venezuela's head of state Nicolas Maduro and took him and his wife to New York where they have been jailed ever since, facing charges of drug trafficking conspiracies, among other things.
with DPA
