Special police forces have dispersed protesters demanding the resignation of Bosnian Serb interior minister Dragan Lukac over a student’s death, detaining several people in the north-western town of Banja Luka, Guardian reported.

Thousands of protesters gathered on Sunday to accuse Lukac and police officials of covering up the truth behind the death of 21-year-old David Dragicevic.

During a march lasting several hours in the town’s centre, the demonstrators prevented a concert by a regional folk singer from taking place, eventually forcing the the event to be cancelled.

In the nine months since Dragicevic was found dead in March in a creek in Banja Luka, after being missing for six days, his father, Davor Dragicevic, has held a daily protest in the town square to demand the truth.

His quest has developed into a larger movement of citizens fed up with corruption and with what they say is Bosnia’s weak rule of law. Smaller-scale protests in solidarity with the grieving father took place in Croatia and Serbia last week.

The police first said David Dragicevic had committed suicide but later said there was a possibility he had been killed. No evidence of murder had been found by the prosecution team handling the case.