Russia has announced the expulsion of seven diplomats from Slovakia and the three Baltic states in a continuation of the diplomatic war sparked by Czech allegations that Russian spies were involved in a deadly arms depot explosion in 2014.

The Russian Foreign Ministry said in statements on April 28 that the ambassadors of the four European nations had been informed that three officials at the Slovak Embassy in Moscow, two officials at the Lithuanian Embassy, and one official of each from the embassies of Latvia and Estonia had been ordered to leave Russia before May 5 for their “pseudo-solidarity” with the Czech Republic.

Earlier this month, the Czech Republic expelled scores of Russian diplomats over the accusations, prompting a tit-for-tat response from Moscow.

Last week, Lithuania, Latvia, and Estonia — all former Soviet republics — said they were expelling Russian diplomats in solidarity with the Czechs, while Slovakia also told Russia three diplomats must leave the embassy in Bratislava over the allegations.

Lithuania said after the announcement that the two diplomats from its embassy “have never carried out activities incompatible with their diplomatic status.”

“The Foreign Ministry also hopes that Russia will change its aggressive foreign policy, stop accusing other states of escalating the situation, and, finally, hear the messages sent to it by the Western community,” it said in a statement.

All of the countries are members of the European Union and the NATO security alliance.