SOFIA (Reuters) - Bulgaria has expelled two Russian diplomats who prosecutors suspect were involved in spying, giving them 72 hours to leave the Balkan country, the foreign ministry said on Wednesday. EU and NATO member Bulgaria, which usually maintains good ties with Russia, has kicked out three other Russian diplomats over espionage allegations since last October. It also declined to grant a visa to Russia’s incoming defence attache in December. “Bulgaria’s foreign ministry has declared two Russian diplomats ‘personae non gratae’ and has informed the Russian embassy with a diplomatic note,” a ministry spokesman said. The Russian Embassy in Sofia said it had received a verbal note concerning staff at its trade mission, but was not provided with any proof that the two had acted in a way incompatible with their official status. “The groundless expulsion of Russian diplomats does not correspond to the traditionally constructive nature of bilateral relations,” it said in a statement on its website. The embassy said the diplomats would leave Bulgaria within the outlined timeline, but Russia would reserve its right to a response in kind. Advertisement Earlier on Wednesday prosecutors said the two diplomats had been seeking classified information on army modernisation plans and the maintenance of military equipment since 2016 and that they aimed to pass it to Russian military intelligence. In a statement, they said the diplomats had made contact with Bulgarians with access to information related to the country’s military-industrial complex and that in some cases financial benefits had been promised and provided. Bulgaria was Moscow’s most obedient satellite in eastern Europe during Soviet times. Despite periodic strains in relations since then, Russia remains Bulgaria’s biggest energy supplier.