Parts of Russian-annexed Crimea were briefly left without electricity on Thursday evening but the Russian energy ministry said power was later restored.
Officials said the blackout was caused by an emergency shutdown of a power plant in Balaklava, which the ministry said resulted from an interruption of its gas supply. It was not clear what caused the malfunction.
Sevastopol, a port that serves as the headquarters of Russia's Black Sea Fleet, was among the areas affected.
Russia annexed Crimea from Ukraine in 2014 and the peninsula has come under frequent Ukrainian attack in the course of the war.