BELGRADE, Serbia >> Thousands of people rallied in Serbia’s capital on Saturday, chanting “Thieves!” and accusing the populist authorities of President Aleksandar Vucic of orchestrating a fraud during a recent general election.

The big rally in central Belgrade capped nearly two weeks of street protests against reported widespread irregularities during the Dec. 17 parliamentary and local ballot that were also noted by international election observers.

The ruling Serbian Progressive Party was declared the election winner but the main opposition alliance, Serbia Against Violence, has claimed the election was stolen, particularly in the vote for the Belgrade city authorities.

Serbia Against Violence has led daily protests since Dec. 17 demanding that the vote be annulled and rerun. Tensions have soared following violent incidents and arrests of opposition supporters at a protest last weekend.

The crowd at the rally on Saturday roared in approval at the appearance of Marinika Tepic, a leading opposition politician who has been on a hunger strike since the ballot. Tepic’s health reportedly has been jeopardized and she was expected to be hospitalized after appearing at the rally.

“These elections must be rerun,” a frail-looking Tepic told the crowd, waving feebly from the stage and saying she doesn’t have the strength to make a longer speech.

Another opposition politician, Radomir Lazovic, urged the international community “not to stay silent” and set up a commission to look into the irregularities and pressure authorities to hold a new election that’s free and fair.

After the speeches, participants marched by the headquarters of the state electoral commission toward Serbia’s Constitutional Court that will ultimately rule on electoral complaints.

A protester from Belgrade, Rajko Dimitrijevic, said he came to the rally because he felt “humiliation” and the “doctoring of the people’s will.”

Ivana Grobic, also from Belgrade, said she had always joined protests “because I want a better life, I want the institutions of this country to do their job.”

It was not immediately clear if or when opposition protests would resume. The rally on Saturday was organized by an independent civic initiative, ProGlas, or pro-vote, that had campaigned for high turnout ahead of the ballot.

Ruling party leader Milos Vucevic said the “small number of demonstrators” at the rally on Saturday showed that “people don’t want them (the opposition.)”

The opposition has urged an international probe of the vote after representatives of several global watchdogs reported multiple irregularities, including cases of vote-buying and ballot box stuffing.

Local election monitors also alleged that voters from across Serbia and neighboring countries were registered and bused in to cast ballots in Belgrade.

Vucic and his party have rejected the reports as “fabricated.”

Saturday’s gathering symbolically was organized at a central area in Belgrade that in the early 1990s was the scene of demonstrations against strongman Slobodan Milosevic’s warmongering and undemocratic policies.

Critics nowadays say that Vucic, who was an ultranationalist ally of Milosevic in the 1990s, has reinstated that autocracy in Serbia since coming to power in 2012, by taking full control over the media and all state institutions.

Vucic has said the elections were fair and his party won. He accused the opposition of inciting violence at protests with the aim of overthrowing the government under instructions from abroad, which opposition leaders have denied.

On Sunday evening, protesters tried to enter Belgrade city hall, breaking windows, before riot police pushed them back using tear gas, pepper spray and batons. Police detained at least 38 people.

Serbia is formally seeking membership in the European Union, but the Balkan nation has maintained close ties with Moscow and has refused to join Western sanctions imposed on Russia over the full-scale invasion of Ukraine.

Russian officials have extended full support to Vucic in the crackdown against the protesters and backed his claims that the vote was free and fair.