Russia says it has given a Bulgarian diplomat 72 hours to leave the country following the expulsion of its military attache in Sofia.

In a December 28 press release, the Russian Foreign Ministry said it had sent the Bulgarian ambassador to Moscow a note announcing that the assistant to Bulgaria’s military attache had been declared “persona non-grata” in response to the “unjustified” removal of a Russian diplomat earlier this month.

Bulgarian authorities on December 18 gave a Russian diplomat 72 hours to leave the EU and NATO member state after prosecutors alleged he had been involved in espionage since 2017.

Prosecutors have said that the diplomat had “collected military information, including about the numbers of U.S. troops deployed on Bulgarian territory during exercises.”

The aim was to transfer this information to Russian military intelligence, they said, adding that they had evidence the diplomat had been in contact with a Bulgarian citizen with access to classified information to whom money had been offered.

It was the sixth case of a Russian diplomat or official at the Russian Embassy in Sofia being expelled for suspected espionage since October 2019.