(Reuters) - Russia's foreign ministry summoned Bulgaria's ambassador, Atanas Krastin, on Monday to protest over Sofia's expulsion of a Russian Orthodox cleric last week, the ministry said in a statement.
Bulgaria expelled one Russian and two Belarusian clerics for carrying out what it described as activities directed against the country's national security and interests.
Bulgaria is a member of NATO and the European Union. Historically warm relations with Russia have come under strain in recent years, especially since Moscow sent tens of thousands of troops into Ukraine.