Bulgaria on Wednesday said it had expelled the correspondent of the Russian state-owned newspaper Rossiyskaya Gazeta, weeks after sending home the head of the local Russian Orthodox Church.
Journalist Aleksander Gatsak had been found to be performing "activity that poses a threat to Bulgaria's national security," Bulgaria's State Agency for National Security said in a statement.
His residency rights had been revoked and an expulsion order was issued in September, the agency added.
"The actions of the agency aim to protect national security, not restrict freedom of speech and expression."
In September, Bulgaria expelled the head of the Russian Orthodox Church in Sofia and two Belarussian priests, accusing them of having interfered in the country's internal affairs.
A member of the European Union and NATO, Bulgaria is a Slavic and Orthodox country with very close historical and cultural ties to Russia.
But relations have been strained since Russia launched its invasion of Ukraine, with Sofia condemning the war and expelling 70 Russian diplomatic staff last year.