Eight people lost their lives and ten others were wounded when a drone struck a passenger bus in a Russia-controlled zone of Ukraine, according to Russian state media.

Denis Pushilin, the Kremlin-backed head of Ukraine's Donetsk region, confirmed the bus was hit in the early hours of Wednesday while traveling from Moscow to Simferopol in Russian-occupied Crimea.

The incident unfolded as the city prepared for its annual International Economic Forum, an event meant to highlight Russia on the global stage.

These strikes follow a major Russian offensive across Ukrainian cities the previous day that left at least 22 dead, among them several women and children.

Russian investigators launched a criminal probe into the event, which they called a terrorist attack on civilians.

Svetlana Petrenko, a spokesperson for the Russian Investigative Committee, said officials are working to identify those responsible for the strike.

Fifty-three passengers were listed for the journey, Reuters noted, though no victim names have been made public so far.

Andriy Kovalenko, who leads Ukraine's center for combating disinformation, spoke of a parallel reality pushed by Russian state propaganda without directly disputing the reports.

He told the BBC that Russia routinely targets civilians with drones, and when evidence surfaces, it resorts to its main propaganda tactic of inventing alternative narratives.

Such stories aim to portray Ukraine mirroring Russian actions in order to justify ongoing terror as retaliation, he added.

The BBC has requested comment from the Ukrainian military.

Russian officials reported intercepting drones over Belgorod, Kursk and other western regions, plus areas near Moscow and the Sea of Azov.

Russia claimed a total of 350 Ukrainian drones were downed overnight.

At least 50 drones were shot down over the Leningrad region northwest of Moscow, according to regional governor Alexander Drozdenko.

The area includes St Petersburg, which is hosting delegates for the economic forum starting Wednesday.

Russian President Vladimir Putin is set to address participants on Friday.

Ukrainian President Zelensky posted on X about hits on key Russian facilities, sharing video of black smoke over St Petersburg and describing the strikes as long-range sanctions while noting military targets struck in the Tambov region.

The overnight actions prompted temporary flight limits at Pulkovo airport, Russian aviation authorities said.

Separately, an 86-year-old woman died in a drone attack in Ukraine's southern Kherson region, according to local military head Yaroslav Shanko.

This formed part of a wider Russian assault that saw 198 drones launched at multiple Ukrainian regions, with 189 intercepted by air defenses.

The latest strikes follow one of Russia's largest attacks on Ukraine since the 2022 invasion, which killed at least 22 people using more than 700 missiles and drones.

Russia's defense ministry framed the operation as a response to earlier Ukrainian actions and said all strike goals were met.

The Kremlin announced it would continue systematic strikes after accusing Kyiv of a deadly dormitory attack in occupied eastern Ukraine in late May.

Kyiv stated it had targeted a Russian military unit.

Kremlin spokesman Dmitry Peskov told reporters Tuesday that this approach would persist, with strikes aimed at Ukrainian military infrastructure.

Additional reporting by Vitaly Shevchenko.