Petro Andriushchenko, an advisor to the Ukrainian mayor of Mariupol, said this in a post on Telegram, Ukrinform reports.
"Stary Oskol in the Belgorod region. UAV sounds. An explosion. A substation is on fire. They are preparing to take over a flash mob 'blackout' from Crimea," the post said.
On Thursday, January 18, some cities in temporarily occupied Crimea were left without electricity. There was no light in Kerch, Sevastopol, Simferopol, Feodosia, Dzhankoi, Saky, in the Leninskyi district of the peninsula and in Krasnoperekopsk.