Several thousand people rallied Sunday in support of a Bosnian father who helped launch a movement for justice and rule of law while pursuing the truth about his 21-year-old son's death.

Bosnians inspired by Davor Dragicevic's quest demanded the ouster of the Bosnian Serb interior minister and top police officials over the death in March death of Dragicevic's son David.

Police initially said it was a suicide, but the young man's family insists he was killed by someone else. Prosecutors opened a homicide investigation that is ongoing.

Davor Dragicevic has accused Serb police officials of protecting his son's killers and says he won't leave a central square in the city of Banja Luka until his demands are met.

"There is no turning back. I have nowhere else to go," Dragicevic told the crowd that came out to back him. "It's New Year's, Christmastime, but where is my David?"

Bosnian Serb officials have denied shielding suspects in the slaying of the younger Dragicevic'. The Serb member of Bosnia's multi-ethnic presidency, Milorad Dodik, has described the protests as "political."

Tensions have soared in the Serb-run part of Bosnia since Tuesday, when police briefly detained Dragicevic and several other people. Bosnia consists of a Serb and a Muslim-Croat entity that were created after a 1992-95 war.

Dragicevic on Sunday reiterated his allegation that Bosnian Serb police brass were defending the people responsible for his son's death.

"I will stand here as long as it takes," he said.

After the main rally, the mourning father's supporters marched through the city chanting "We are with you Davor" and booing as they passed government buildings.

Dragicevic's "Justice for David" movement has inspired months of anti-government protests that reflected popular discontent over corruption and unemployment in the Balkan nation.