Serbia is set to hold a presidential run-off later this month as none of the candidates won over 50 percent of the vote on Sunday, Serbian news agency Tanjug reported.
Incumbent Boris Tadic of the pro-EU Democratic Party won 26.8 percent, while Tomislav Nikolic of the Serbian Progressive Party garnered 25.6 percent, according to projections of pollster CeSID.
The two front-runners among the 12 presidential candidates would enter a run-off on May 20, according to the country's electoral law.
Meanwhile, preliminary results of the parliamentary election, held in parallel with the presidential race, showed that the Serbian Progressive Party claimed a narrow victory with around 24.7 percent.
Serbian voters cast their ballots on Sunday in elections for president, parliament and local authorities. Polling stations were also set up in Kosovo, which declared independence in 2008 but Serbia regards as its southern province.