Authorities in Bulgaria have given two Russian diplomats 72 hours to leave the country for alleged espionage.
Prosecutors announced on Friday that six people had been arrested on suspicion of spying for Russia, including several defence ministry officials in the European Union and NATO member state.
On Monday, they said that “preliminary investigations have shown that two Russian nationals carried out intelligence activity incompatible with diplomatic relations.”
The foreign ministry said that two Russian diplomats had been “declared persona non grata and given 72 hours to leave the country”.
According to the Bulgarian television station Nova, the diplomats were officers working for Russian military intelligence.
Prosecutors alleged that those arrested last week belonged to a spy ring led by a Bulgarian former intelligence officer whose wife played the role of intermediary with the Russian embassy.
The Russian embassy warned in a statement on Facebook that it could respond to the expulsions.
It expressed “regret that once again this unfounded action by the Bulgarian authorities will not contribute to constructive dialogue between Russia and Bulgaria”.
“Russia reserves the right to take retaliatory measures,” it said.
Relations between Bulgaria and Russia have been hit by several spy scandals in recent years.
Between October 2019 and the end of 2020, five Russian diplomats and a technical assistant at the Russian embassy were expelled from Bulgaria.
The disputes have soured relations between the two former allies, which had maintained their close cultural, historical and economic ties even after the fall of communism in 1989. Bulgaria was considered Russia’s closest ally during the Cold War.
The latest case came with relations between the EU and Russia strained by the poisoning and imprisonment of opposition politician Alexey Navalny and the EU’s decision to sanction high-ranking Russian officials over the affair.
On Monday, Polish Foreign Minister Zbigniew Rau said his country and fellow EU member state “stands firmly with our friend and NATO ally Bulgaria in its actions to protect sovereignty against Russia’s hostile, spy activity”.
During the weekend, the United States also said it “stands with Bulgarians against these malign activities on their territory” while the UK expressed its full support for “Bulgaria’s efforts in disrupting an alleged spy ring and taking steps to tackle Russia’s hostile actions”.
NATO Secretary-General Jens Stoltenberg told Bulgarian Prime Minister Boyko Borissov by telephone on Monday that the alliance should stand united against any malign activities targeting its member states, the government press office said. Borissov has called on Russia to stop spying in the Balkan country.
Fourteen years after joining the EU, Bulgaria is still dependent on Russian energy. With its resorts on the Black Sea, the country is very popular with Russian tourists and property owners.