St Petersburg Governor Alexander Beglov said the city of 6 million had been subjected to a "large-scale" drone attack, with the city's oil terminal struck. He said there were no casualties and that the aftermath of the attack had been dealt with.
Leningrad region Governor Alexander Drozdenko said drones had struck the port of Vysotsk, about 170 km (105 miles) northwest of St Petersburg on the Baltic Sea. The port handles oil, grain, coal and liquefied natural gas.
Drozdenko said 72 drones had been shot down over the Leningrad region.
In a post on Telegram, Ukrainian President Volodymyr Zelenskiy said: "Ukraine's defence forces struck port oil infrastructure that generates revenue for Russia's war, and also hit Kronstadt, an important military target more than 850 km (528 miles) from Ukraine's state border."
There was no information from Russia on a strike on Kronstadt, a major naval base close to St Petersburg that Ukraine hit in a previous attack on the city in June.
Ukraine has intensified strikes on Russian energy infrastructure this year, causing fuel shortages in parts of Russia.
Elsewhere, the governor of Russia's Bryansk region, as well as the Russian-installed governor of Crimea, said that drone strikes had killed one person in each region, with several more wounded.
South of St Petersburg, the governor of Pskov region said more than 30 drones had been shot down overnight. He reported minor damage and injuries, including to a factory in the town of Velikiye Luki.
