Czech Prime Minister Andrej Babis has said that he has asked the European Council to condemn Russia for its involvement in the deadly explosion of an arms depot on Czech soil in 2014.

Asked whether he had brought up the explosion during an informal two-day summit of EU leaders taking place in Portugal, Babis told journalists on May 8 that he had “called for the [European] Council to condemn and declare such actions as unacceptable” when it presents its concluding statements at an EU summit scheduled to take place in Brussels later this month.

Babis said that he called on the council to make it clear “that it is impossible to accept such actions, and that we must view an attack on one [EU] member state as an attack on all.”

Babis on April 17 announced that investigators from the Czech intelligence and security services had provided “unequivocal evidence” that there was “reasonable suspicion regarding a role of members of Russian military intelligence GRU’s unit 29155 in the explosion of the munition depot in Vrbetice in 2014.”

Two men were killed in the blast.

In response, the Czech government announced the expulsion of 18 Russian diplomats it considered to be spies, setting off a string of tit-for-tat moves between Prague and Moscow.

Russia has denied involvement in the explosion.