Police in Banja Luka issued an arrest warrant on Monday for Davor Dragicevic and four others after Dragicevic led months-long protests trying to press authorities to solve the March murder of his son, according to the Anadolu and FENA news agencies.

Police in Bosnia's Serb-dominated semi-autonomous entity, Republika Srpska (RS), issued the warrant Monday morning after protesters marched the streets of Banja Luka and obstructed New Years celebrations and a concert.

The ‘Children’s New Year’ celebration which should have taken place in Banja Luka on Monday afternoon was cancelled due to fear the ‘Justice for David’ group could confront authorities again and endanger the children, the city’s mayor announced.

“Following yesterday’s unfortunate scenes and the forceful stopping of a scheduled concert, children must not in any way be endangered and that is why the planned children’s events are being cancelled,” Mayor Igor Radojicic said.

The group on protested on Sunday in front of the buildings of the RS Government, the RS National Assembly, the RS Presidential Palace, Republika Srpska’s public broadcaster, RTRS, and the office of the director of the forensic pathologist who performed the autopsy of late 21-year-old David Dragicevic after his March murder.

The victim’s father, Davor Dragicevic, initiated months-long rallies against police and prosecutors whom he is accusing of covering up his son’s murder to protect the politically connected perpetrators.

The protests have grown into the longest and largest anti-government movement in Bosnia and have drawn hundreds of thousands of sympathisers who have staged rallies of support in Sarajevo, Mostar, Tuzla, Belgrade, Zagreb, Novi Sad and other cities in the region.

Protesters prevented an open-air concert on Sunday evening and pledged to obstruct New Years celebrations in Banja Luka if the interior minister of Republika Srpska does not resign.