Serbia's President Aleksandar Vucic has claimed a sweeping victory in Sunday's parliamentary elections amid accusations of vote rigging.

Official results were set to be announced late Monday, but the president appeared certain of his Serbian Progressive Party's (SNS) performance, just hours after the polls closed.

"We will have an absolute majority in parliament with 127 seats," Vucic told reporters during a press conference, saying around 76% of ballots had been counted.

Even though Vucic was not personally on the ballot in Sunday's parliamentary and local elections, the contest was largely seen as a referendum on his government.

"My job was to do everything in my power to secure an absolute majority in the parliament," Vucic told reporters as he celebrated what he said was the SNS's victory.

The right-wing SNS looked poised to expand their presence in the 250-seat parliament with Sunday's results. During the last election in 2022, the party secured just 120 seats, resulting in a coalition government.

The SNS still faced potentially hard-fought municipal races in the capital Belgrade, particularly from the loose coalition of opposition parties and candidates running under the Serbia Against Violence banner.

That movement was formed in the wake of back-to-back mass shootings earlier this year. They spurred hundreds of thousands to take to the streets in rallies that morphed into anti-government protests over several months.

The contest was not without controversy, with the opposition complaining of foul play.

"We call on all political actors in Serbia and the international community not to remain silent in the face of this brutal robbery," said Djordje Miketic, a candidate linked with the Serbia Against Violence movement.

Earlier Sunday, opposition leader Radomir Lazovic also complained of numerous "irregularities," citing alleged "vote buying" and "falsification of signatures."

"We may have had the dirtiest electoral process," he added.

Posts on social media also fueled rumors that the government allowed unregistered voters from neighboring Bosnia and Herzegovina to cast ballots illegally in the election.

Prime Minister Ana Brnabic dismissed the claims, accusing the reports of spreading chaos.

'Landslide'

Vucic had been beaming with confidence as voting got underway Sunday, predicting a landslide victory even then.

The opposition pinned its hopes on a high turnout.

"I hope that by the end of the day, we'll have a big turnout ..., and that the voters will have the freedom to express their will," said Dobrica Veselinovic, one of the leaders of the opposition Serbia Against Violence movement.

Vucic was omnipresent ahead of the vote – plastered on billboards and skyscrapers and the focus of wall-to-wall coverage on news channels.

By the time polls opened at 7 a.m. (6 a.m. GMT), lines had already formed in Belgrade as people waited to cast their ballots.

"I came early to support our president, he must continue his work," said Stojan Milenkovic, a 67-year-old retiree.

Others were hoping the contest would bring change to the country's political scene.

Along the southern border, hundreds of ethnic Serbs from the former breakaway province of Kosovo crossed into Serbia to cast their votes.

The voters loaded onto over a dozen buses and spent nearly two hours crossing the border, following the failure of Belgrade and the Pristina government to iron out a deal that would have allowed the Serbs to vote inside Kosovo.

Muzzled media

Like many countries across the globe, Serbia has been battered by double-digit inflation.

To blunt the hard edges of rising prices ahead of the elections, Vucic unleashed a barrage of state spending including pension increases and cash payouts to the elderly.

He has also vowed to double average monthly salaries in the coming years.

Vucic has used his more than a decade in office to consolidate control over the levers of power, including de facto control over the media.

He called the snap elections in November, the latest example of how governments under his rule rarely serve out their term – a move critics say is designed to keep the opposition off balance.

The contest comes less than two years after the last round of presidential and parliamentary voting, which saw Vucic and the SNS tighten their grip on power.