Serbian Progressive Party leader and presidential candidate Tomislav Nikolic (2nd L), and his wife Dragica cast their ballots at a polling station in Belgrade, Serbia, May 6, 2012. The voting of Serbia's presidential and parliamentary elections started on Sunday morning. (Xinhua/Emilvas)

Serbian voters cast their votes on Sunday in elections for president, parliament and local authorities, a ballot which would bear on the country's potential European Union (EU) membership.

The two leading contenders in presidential election were the liberal incumbent Boris Tadic, leader of the pro-EU Democratic Party, and Tomislav Nikolic, backed by his populist Serbian Progressive Party, which has been a narrow favorite in pre-election polls.

Tadic, 54, in his election program, focused on a bid to join the EU and economic reform in an effort to win a third term, while Nikolic, his arch rival, pledged the country to be a "bridge" between East and West.

The election came as the Serbia struggled in its economic malaise, with an unemployment rate rocketed to some 24 percent.

In an interview with Xinhua, a mother of six complained that she had "no right for child welfare, no right for their scholarships, no right on anything." The current "catastrophic authority" has pushed her to vote for Nikolic, she said.

Meanwhile, a butcher worker, who voted for Tadic last time, said he would not back anyone this time, saying that he "lost trust in every political party" as "everything has gone wrong" during Tadic's mandate.

The election, kicked off at 7:00 a.m. local (0500 GMT), would close at 8 p.m. (1800 GMT), as over 6.7 million registered voters were to cast their ballot in 8,930 polling stations across the country.

Around 90 polling stations in Kosovo were opened in the morning. "So far, no irregularities have been reported," said Miograd Petrovic, a member of the state electoral commission.

The the Organization for Security and Cooperation in Europe (OSCE) has reached an agreement with the authorities in Kosovo for facilitating the elections.

"There were minor delays of a technical nature in a few locations but these have all now been resolved," said head of OSCE Mission in Kosovo Werner Almhofer. .

In 2008, Kosovo declared independence, while Serbia insists Kosovo is its southern province.

Maintaining they are part of Serbia, the ethnic Serbs in Kosovo have resisted institutions of the ethnic Albanian-dominated Kosovan government and vowed to hold local elections.

Serbian Deputy Prime Minister Ivica Dacic warned recently of potential violence, and NATO has sent in 700 additional troops to Kosovo ahead of elections in an attempt to prevent possible incidents.