Police in Serbian capital fire tear gas at election protesters as EU, U.S. call for reforms

Police in Serbia fired tear gas to prevent hundreds of opposition supporters from entering the capital's city council building Sunday in protest of what election observers said were widespread vote irregularities during a general election last weekend.

The country's populist authorities have denied rigging the vote. President Aleksandar Vucic said Sunday that those claims were blatant "lies" promoted by the political opposition.

Shielded riot police barricaded themselves inside Belgrade's city hall, firing tear gas as hundreds of opposition protesters broke windows at the entrance of the downtown building.

The protesters shouted "Open the door" and "Thieves." Tey also pelted the building with eggs. Some chanted "Vucic is Putin," comparing the Serbian president with Russia's leader.

There were no immediate reports of injuries.

EU, U.S. call for election reform

The European Union and the United States urged Serbia to address concerns about its electoral process after independent observers found worrying irregularities including vote buying during last weekend's snap election.

The electoral process in Serbia, which has been a candidate to join the EU since 2012, needs to be improved significantly, two EU commissioners said on Tuesday.

"We conclude with concern that the electoral process requires tangible improvement and further reform, as the proper functioning of Serbia's democratic institutions is at the core of Serbia's EU accession process," EU commissioners Josep Borrell and Oliver Varhelyi said in a joint statement.

The country's ruling Serbian Progressive Party (SNS) gained an unfair advantage in snap parliamentary elections through media bias, the improper influence of President Aleksandar Vucic and voting irregularities such as vote buying, an international monitoring mission said on Monday.

The U.S. State Department said on Tuesday it was reviewing the findings of the Organization for Security and Co-operation in Europe (OSCE) observer mission. Washington urged Serbia to work with the OSCE to address "unjust conditions" surrounding the electoral process.

The OSCE "did find as well that the elections were marred by numerous procedural deficiencies (like) pressure on public employees, and misuse of public resources, and that these factors together with the ruling party's systemic advantages create unjust conditions. So we will urge Serbia to work with the OSCE to address these concerns," a State Department spokesperson said.

The populist SNS won 46.72 per cent of the votes in Sunday's elections, according to state election commission preliminary results, based on the count from 96 per cent of the polling stations. The centre-left opposition alliance Serbia Against Violence came second with 23.56 per cent of the votes and the Socialist Party of Serbia third with 6.56 per cent.

Observers also said there was misuse of public resources, a lack of separation between official functions and campaign activities, voter intimidation and vote buying.