Thousands of opposition supporters rallied peacefully in Belgrade, Serbia, in an anti-government protest to demand the annulment of December’s elections, which were described by international observers as unfair, writes Reuters.

The populist ruling Serbian Progressive Party (SNS) won 46.72% of the votes in the snap parliamentary and local elections. But an international monitoring mission said the SNS gained an unfair advantage through media bias, the improper influence of President Aleksandar Vucic, and voting irregularities such as vote-buying.

Vucic and his allies said the elections were fair.

The rally was also staged to mark the sixth anniversary of the killing of Oliver Ivanovic, a moderate Kosovo Serb politician. Ivanovic was gunned down in front of his party office in 2018 in the ethnically divided town of Mitrovica, a predominantly Serb area of mainly Albanian Kosovo, which declared independence from Belgrade in 2008.