Ukrainian drones rained down on St. Petersburg overnight, striking key infrastructure and wounding several people, just hours before Russian President Vladimir Putin’s signature economic forum drawing thousands of attendees opened in the city.

Hundreds of drones hit several Russian cities, with Kyiv claiming to have struck a naval warship and other key assets in a major attack reaching as far as Moscow.

Three districts of St. Petersburg were targeted in Ukrainian drone assault, according to its governor Aleksandr Beglov – shortly before the St. Petersburg International Economic Forum (SPIEF), often dubbed Putin’s version of Davos, began on Wednesday.

Kyiv has stepped up attacks hitting key Russian oil assets in recent months, firing hundreds of long-range drones, squeezing fuel supplies and compounding economic strains for residents. In May, Ukrainian forces carried out their largest assault on Moscow in more than a year, state media reported at the time.

That threat permeated another major event in Russia early last month, when Putin hosted a scaled-back Victory Day Parade in Moscow after intensified strikes inside the country, including a drone attack on a residential building in the capital days earlier. The Kremlin has historically used the parade to display its military prowess.

In the latest assault, Russian air defenses intercepted and destroyed more than 350 Ukrainian drones over areas both close to the border and deeper into the country including the Leningrad region and the western city of Novgorod, according to the Russian Ministry of Defense.

The Ukrainian military claimed to have hit a Russian corvette dubbed the “Boikiy” along the Kronstadt island port near St. Petersburg. Belonging to the Russian Navy Baltic Fleet, the warship is packed with “guided missile weapons,” it said. Moscow has used to the Boikiy to escort vessels in its shadow oil fleet, which the Kremlin has repeatedly used to evade sanctions, the military added.

CNN has reached out to the Russian defense ministry to confirm the attack.St Petersburg, Russia

On Tuesday, Ukraine also launched strikes on “critical infrastructure facilities” in Smolensk, a city in western Russia close to the Belarus border, the governor Vasiliy Anokhin said.

Two firefighters were killed there while trying to extinguish a blaze “caused by debris from a downed enemy drone,” Anokhin said, adding that two other firefighters and one civilian sustained minor injuries.

Ukrainian President Volodymr Zelensky reported “positive results” from long-range strikes against “key targets,” including the St. Petersburg oil terminal, one of the largest oil transshipment complexes in northwestern Russia. The terminal plays a “crucial role” in Russian fuel exports and logistics, according to the general staff of the Ukrainian Armed Forces.

Other targets included a facility in the Tambov region that Zelensky said was involved in the production of Russian weapons.

“Ukraine’s plan for long-range strikes is being carried out exactly as needed to bring peace closer,” the Ukrainian president added.

Footage posted by Zelensky showed fiery explosions and several blazes at one Russian facility. In another of the clips, a huge plume of thick, black smoke is seen behind a high-rise building.

Ukraine has this year rapidly developed its medium and long-range drones to attack Russian targets, including Moscow’s oil facilities and other locations far beyond the front lines.

Moscow doubled down on threats of intensified strikes following the Ukrainian assault on Tuesday night. On Wednesday, Kremlin spokesperson Dmitry Peskov warned that “our responses will be systemic in nature,” in a call with journalists.

Economic forum

Twenty thousand people from more than 100 countries have confirmed their participation at the St. Petersburg economic forum, Russian state media TASS reported on Tuesday, citing Putin’s aide, Yury Ushakov. Putin will deliver a “grand speech” to an audience on Friday, Ushakov told reporters.

The Russian president will primarily discuss “economic problems” alongside “political issues,” Peskov said.

Among those high-profile guests are the American far-right podcaster Candace Owens, and the US Commission of Fine Arts Chairman Rodney Mims Cook, Jr, according to the forum program. Appointed to the government commission by President Donald Trump, Cook is the first US official to attend the forum since 2017.

The self-proclaimed misogynist influencer Andrew Tate and his brother Tristan also posted that they are in Moscow, though is unclear if they are attending the forum.

Officials at St. Petersburg international airport resumed operations Wednesday afternoon, they posted on Telegram, after the local airspace had been restricted, delaying around two dozen flights.

Moscow and Kyiv have escalated aerial bombing in recent weeks. Just on Tuesday, Russia launched a lethal barrage hitting the capital Kyiv and the central city of Dnipro in a broad-ranging offensive that inflicted one of the deadliest attacks for months.

At least 23 people were killed in the overnight assault, including seven people in Kyiv and 16 others in Dnipro, according to Ukrainian authorities.

United Nations Secretary-General António Guterres said he “strongly” condemned the attacks, in which more than 600 drones and dozens of missiles were fired on Ukraine, according to the military, hitting key civilian infrastructure. (CNN)