Ukrainian drones have struck Russia’s Baltic Sea port of Primorsk and the NORSI oil refinery in the central Nizhny Novgorod region, according to Ukrainian drone forces commander Robert Brovdi.
The overnight attacks were first reported by Russian officials on Sunday.
Alexander Drozdenko, governor of Russia’s northwestern Leningrad region initially said a pipeline was damaged at Primorsk, one of Russia’s main oil exporting outlets. He later said in a post on Telegram that a fuel reservoir in the port area leaked when it was hit by shrapnel.
In Nizhny Novgorod, Governor Gleb Nikitin said a fire had broken out at the NORSI oil refinery, Russia’s fourth largest. He said two facilities at the plant were hit.
He said a power station and several houses were damaged during the attack although there were no injuries, according to preliminary information.
Primorsk, which is between the Finnish border and St Petersburg, was also attacked in March when an oil depot was set ablaze.
The port is used by Russia’s oil transport company Transneft to ship oil abroad.
NORSI, which is also Russia’s second largest producer of petrol, can process 16 million metric tonnes of oil per year, or about 320,000 barrels per day.
Ukraine has stepped up attacks on Russian oil infrastructure in recent months in an effort to reduce a key source of revenue that funds Moscow’s war on Ukraine.
At some point last month, about 40 percent of Russia’s oil exporting capabilities were shut down due to the attacks, the closure of the Druzhba pipeline in Ukraine and the seizure of Russia-linked tankers.
Diplomatic efforts to end Russia’s war on Ukraine have stalled in recent months.
The United States, Russia and Ukraine have held three rounds of high-level talks in Abu Dhabi and Geneva this year in a bid to negotiate an end to the war. No progress was made on the vital question of territorial concessions in eastern Ukraine.
A fourth round of talks scheduled for last month was postponed due to the US-Israel war on Iran.
DW Russian 
