Russian President Vladimir Putin (C) meets with Transport Minister Vitaly Savelyev (L) and the Russian Railways CEO Oleg Belozyorov at the Kremlin in Moscow on June 5, 2023. AFP
The hacking comes amid several reported incursion attempts and intense shelling in southwestern Belgorod, and as Kyiv says it is preparing a long-expected counteroffensive.
The fake message, still circulating on social media, said that "Ukrainian troops armed to the teeth by NATO and with Washington's consent and support have invaded the Kursk, Belgorod and Bryansk" territories.
The voice, very similar to Putin's, also announced martial law, general mobilisation and the evacuation of civilians in those three regions.
"This was indeed a hack," Kremlin spokesman Dmitry Peskov was cited as saying by state-run agency RIA Novosti.
"Control has already been restored."
The Belgorod region administrative centre said the message was a "deep fake" aiming to "sow panic among peaceful Belgorod residents."
The Voronezh region neighbouring Belgorod also warned its residents of a "hacking of radio broadcasting frequencies" and said "there is no cause for concern."
The MIR radio station said the hacking, which it called "an absolute fake and a provocation", had lasted around 40 minutes.