Belgium has decided to expel 21 Russian diplomats for their involvement in espionage and activities threatening the country’s security, Foreign Affairs Minister Sophie Wilmès announced on Tuesday.

Speaking before the Belgian parliament, Wilmès said the officials have 15 days to leave the country.

Belgian state security and the intelligence service had investigated envoys suspected of breaching the Vienna Convention on international relations and put together the list, Wouter Poels, a spokesperson for the foreign ministry, said, adding that the names were communicated to the Russian ambassador to Belgium when he was summoned to the ministry on Tuesday afternoon. The list will not be made public.

Wilmès noted that this decision “was not a sanction,” and that “diplomatic channels remain open with Russia; the Russian embassy can continue to operate.”

In a statement, Russia’s embassy in Belgium said it “dismissed these accusations as completely unfounded and stressed that this decision deals a serious blow to Russian-Belgian relations.”

The Belgian minister said the decision to expel the diplomats was taken in coordination with like-minded countries: The Netherlands decided to expel 17 diplomats on Tuesday, and Ireland did the same with four diplomats earlier the same day.

In a statement on the Dublin expulsions, Irish Foreign Minister Simon Coveney said their “activities have not been in accordance with international standards of diplomatic behavior.”

The Russian embassy in Ireland called the expulsions “arbitrary and groundless,” and predicted that the move “will not go unanswered.”

Ireland has an ambassador and five staff in Moscow.