SARAJEVO (Reuters) - Police dispersed activists gathered at the central square in the northwestern Serbian city of Banja Luka on Tuesday following the arrest of a man who had been leading protests demanding the truth about the murder of his son.

Davor Dragicevic, who accused authorities in Bosnia’s Serb Republic of concealing the murder of his son David for political reasons, was arrested early on Tuesday when police raided his house after he failed to show up for questioning.

The police said he had been arrested for security reasons.

They also briefly detained his former wife, several other protesters, including opposition politicians, and a journalist taking photographs of Dragicevic travelling to hospital.

Hospital authorities said Dragicevic was not suffering from any injuries. One policeman was injured in scuffles with protesters.

Dragicevic said his 21-year-old son, who was found dead in March in a creek in Banja Luka, was captured, tortured and brutally murdered. The prosecution completed its case but no one was found guilty of murder.

The European Union delegation and the office of Bosnia’s international peace overseer expressed concerns about the arrests and urged all sides to refrain from violence.

“We have asked the Republika Srpska Ministry of Interior for an immediate explanation of the ongoing arrests of different persons associated with the ‘Justice for David’ movement,” they said in a joint statement.

The association of Bosnia’s journalists and the Transparency International corruption watchdog also condemned the arrests, saying they represented “political persecution” by the regime.

Police in combat gear removed an improvised memorial for David Dragicevic from the square and pushed back protesters who moved to a park in Banja Luka.

In Sarajevo, where another father is demanding the truth about his son’s murder, a protest in solidarity for Dragicevic was scheduled for the evening.

Sources said police were ordered to clear the square of activists and prepare it for public New Year celebrations which Dragicevic had threatened to obstruct.