Russia's Foreign Ministry notified on Thursday Bulgarian Ambassador to Russia Atanas Krastin that it had designated a Bulgarian embassy official as persona non grata, the ministry said.
"[On Thursday], the Russian Foreign Ministry gave Bulgarian Ambassador to Russia Atanas Krastin a notification letter that an employee of the Bulgarian embassy had been declared as a persona non grata. The measure is an in kind response to Bulgaria's decision to expel a Russian diplomat from the country in October," the ministry said.
Earlier this year, a Russian diplomat was expelled from Bulgaria over allegations that he had been spying for Moscow and collecting classified data since 2018. Moscow said it would respond to the expulsion of its diplomat.
Bulgarian authorities charged Nikolai Malinov, chairman of the National Russophile Movement in Bulgaria, with spying for some Russian institutions and organisations, including the Russian Institute for Strategic Studies, and of laundering money that he had received from them.
The Bulgarian Foreign Ministry demanded that Russia recall its diplomat after the country's prosecutor general said that an investigation against Malinov was terminated because of his diplomatic status.