Authorities in the Balkan country have declined to be drawn on the possible motive for the killings, but speculation has focused on tensions with the ethnic Albanian minority after bouts of intercommunal violence this year, Reuters said.

Several hundred youths of Macedonia's Slavic-speaking majority, many of them in football shirts and scarves, protested in Skopje's main square and in front of parliament, chanting nationalist and anti-Albanian slogans.

Violence broke out when riot police stopped them from marching across a bridge to a mainly Albanian area of the capital, and the youths began throwing stones, a Reuters photographer at the scene said. Police with batons dispersed most of the crowd and guarded the bridge.