Hungary has ordered 10 Russian diplomats to leave the country, accusing them of carrying out “unacceptable” activities that were incompatible with their diplomatic status.

Hungary’s Deputy Prime Minister and Foreign Minister Anita Orban said the decision was made to protect the country’s security and sovereignty, while stressing that diplomatic relations with Russia would continue.

Russia condemned the move and promised a “harsh and painful” response, raising concerns about further deterioration in relations between the two countries.

The decision is particularly significant because Hungary had maintained warmer relations with Moscow than many other European Union members and had not previously expelled Russian diplomats over the war in Ukraine, Al-Jazeera has reported.

The European Union welcomed Hungary’s decision as legitimate, while saying it would continue coordinating closely with Budapest over the situation.