The Bulgarian ambassador to Moscow arrived at Russia's foreign ministry on Tuesday, the RIA news agency reported, against the backdrop of a spying scandal that saw two Russian diplomats expelled from Bulgaria last month.
Russia said in March it reserved the right to take retaliatory measures after Sofia kicked out the diplomats for suspected espionage. The expulsions came after prosecutors charged six people, including current and former military intelligence officers, with spying for Russia.
(Reporting by Anton Kolodyazhnyy; Writing by Alexander Marrow; Editing by Mark Trevelyan)
