The European Union announced plans to send peacekeepers to Bosnia after the country’s highest court suspended laws passed by the regional entity predominantly composed of ethnic Serbs.

EU reserve peacekeeping forces arrived in the country on Wednesday, a day after NATO Secretary General Mark Rutte confirmed support for Bosnia’s territorial integrity. Italian and Czech troops landed in Sarajevo, where they were greeted by EUFOR forces. Romanian troops, military cargo, and helicopters are expected to arrive in the coming days.

Rutte assured that NATO provides “steadfast” support for Bosnia’s territorial integrity, as recent actions by Bosnian Serbs have heightened tensions nearly 30 years after the end of the war.

The President of the Republika Srpska (RS), Milorad Dodik, introduced laws prohibiting the activities of state security bodies and judicial institutions in the territory, which covers about half of the country. In response, the Bosnian and Herzegovinian prosecutor’s office ordered the detention of Dodik and two of his supporters, accusing them of attempting to undermine the constitutional order.

On Wednesday, the Bosnian state prosecutor issued arrest warrants for three senior officials from the Republika Srpska, including Dodik. However, Dodik, who had previously declared his refusal to recognize the decisions of Bosnian courts, rejected the charges and refused to travel to Sarajevo for questioning.