Shostka, Ukraine - A Russian drone strike on a railway station in the northeastern Ukrainian region of Sumy wounded at least 30 people, President Volodymyr Zelensky said Saturday.

Russia's army has repeatedly targeted Ukraine's railway infrastructure since invading in February 2022.

Zelensky called the strike on Shostka station in Sumy "savage."

"So far, we know of at least 30 victims" including passengers and railway staff, he said.

He posted a video showing a mangled train carriage engulfed in flames with twisted metal and busted windows.

"The Russians could not have been unaware that they were striking civilians," he added.

The site is around 30 miles from the Russian border.

A separate wave of overnight strikes by Russia's army on Saturday cut off power to some 50,000 households in the northern Chernigiv region.

Ukraine's army on Saturday also claimed to have struck a major oil refinery in Russia's northwestern Leningrad region.

Kyiv has vowed to increase its own long-range drone attacks on Russian energy sites, in what it calls fair retribution for Russia's daily attacks on its cities and power grid.