The authorities of the Crimean peninsula annexed by Russia announced Thursday that a power plant had been targeted there overnight by a drone attack, which did not cause major damage.

"Today night there was an unmanned aerial vehicle attack on the Balaklava thermal power plant," Sevastopol Governor Mikhail Razvojayev said on Telegram. “The transformer sustained minimal damage. There were no casualties,” he added.

Mr. Razvojayev clarified that there was “no threat to the electricity supply” and that “the incident does not affect the electricity supply of Sevastopol and the peninsula”.

The plant's transformer, which caught fire, "was under maintenance and not working," he said, adding that "workers at the plant quickly managed the fire".

His statement comes as Ukraine continues its counter-offensive in the south of the country.

Russian forces have stepped up their strikes against Ukraine's energy infrastructure in recent weeks.

Russia annexed Crimea in 2014 and kyiv aims to reconquer it.