Moscow in retaliation for an expulsion of Russian diplomats from Spain declared 27 diplomats of that country personae non gratae, the Russian Foreign Ministry said in a statement on Wednesday.

"Spanish Ambassador to Russia Marcos Gomez Martinez was summoned to the Russian MFA on May 18," the statement said. "Russia issued him a strong protest in connection with Madrid’s provocative declaration of 27 employees of Russian diplomatic missions in Spain persona non grata."