KYIV/MOSCOW - Ukrainian President Volodymyr Zelensky said on Wednesday that Ukrainian forces had struck Russia's St Petersburg Oil Terminal overnight.

"The distance from Ukraine's state border to this facility of Russia's oil industry, which serves the war, is about 1,100 kilometers," Zelensky wrote on X.

He said Ukrainian forces also hit "pure military targets" at the Kronstadt naval base, as well as a facility in Russia's Tambov region involved in weapons production.

The St Petersburg Oil Terminal is one of the largest petroleum transshipment facilities in northwestern Russia, with an annual handling capacity of 12.5 million tons.

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Leningrad Regional Governor Alexander Drozdenko said a total of 50 drones were shot down in the region on Wednesday, ahead of an international economic forum in Russia's second-largest city of St Petersburg, which is surrounded by the region.

"Fifty UAVs have been shot down over the territory of the Leningrad Region. Combat operations are continuing," Drozdenko said on social media Max.

St Petersburg Governor Alexander Beglov said Wednesday that drones hit infrastructure in several districts of St Petersburg, causing damage and injuring several people, and comprehensive security measures have been taken to ensure the safety of the forum participants.

Russia's Federal Air Transport Agency said temporary restrictions have been imposed on arrivals and departures of aircraft at St Petersburg's Pulkovo Airport due to the drone attack.

The 29th St Petersburg International Economic Forum is to be held from Wednesday to Saturday.

Meanwhile, seven people were killed and 11 others wounded in a Ukrainian drone attack on a civilian bus in the Donetsk region, regional leader Denis Pushilin said Wednesday.

“In Yenakiyevo, an attack was carried out by a strike UAV on the 'Moscow-Simferopol' scheduled bus. According to preliminary information, seven civilians were killed," Pushilin said on social media.

Another 11 people sustained injuries of varying severity and are receiving medical care.

"I express my sincere condolences to the families and loved ones of the victims. I wish the injured a speedy recovery," Pushilin wrote.

Kremlin: Russia launching systemic strikes

On Tuesday, Kremlin spokesperson Dmitry Peskov said Russian armed forces are launching systematic strikes against Ukraine's military infrastructure in Kyiv and other cities.

The spokesperson said Russia remains open to peace talks with Ukraine, but the conflict will continue if Ukraine continues to reject "genuine negotiations and serious decisions" aimed at achieving a peaceful settlement.

He added that negotiations on the Ukraine conflict remain on hold, although Moscow is maintaining contact with Washington through existing channels.

Russia's Foreign Ministry said on May 25 that the Russian armed forces were launching "consistent, systematic strikes" on Ukrainian military-industrial facilities in Kyiv following the drone attack on a college building in Starobelsk in the Luhansk region.

Ukraine denied responsibility for the attack, saying its forces strike only military facilities and objects used for military purposes in accordance with international humanitarian law. 

In Kyiv, Ukraine's Energy Ministry said a Russian missile and drone attack on Ukraine's energy infrastructure overnight left residents in eight regions without electricity.

An energy company's production facilities and infrastructure in Kyiv were damaged. Two employees were injured and hospitalized, according to a statement from the ministry.

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The strikes also targeted Ukraine's oil and gas facilities, causing damage, the statement said.

Russia launched 656 drones and 73 missiles at Ukraine overnight in the latest wave of attacks, according to the Ukrainian Air Force. Ukrainian air defenses intercepted 602 drones and 40 missiles.

At least 16 people were killed, including five in Kyiv, and more than 100 others were injured in the strikes, according to the preliminary reports from Ukrainian authorities.