Russia’s foreign ministry said it summoned the Swedish ambassador to Russia and “strongly protested” the expulsion of Russian diplomats and Sweden’s “military support to the Kyiv regime.”

It also accused Sweden of “covering up the crimes of Ukrainian nationalists against the civilian population of Donbas and Ukraine,” referring to a region in eastern Ukraine, parts of which are controlled by pro-Russia separatists, Alarabiya News reports.

“In response to this, the Russian side decided to declare persona non grata three diplomats of the Swedish embassy in Russia,” the ministry said.

In early April, Sweden said it was expelling three Russian diplomats who conducted “illegal operations,” following similar moves by other EU allies.

Sweden’s Foreign Minister Ann Linde said the action was “very regrettable,” but said that a total of four diplomats had been expelled – three from the embassy in Moscow and another at the Swedish consulate in Saint Petersburg.

In a written response to AFP, Linde stressed that Sweden expelled the Russians because they had conducted operations that “violated the Vienna Convention on Diplomatic Relations,” but claimed the Swedish diplomats had conducted “traditional diplomatic activities.”

“Sweden will respond in an appropriate manner to Russia’s unwarranted and disproportionate actions,” Linde said.