They bring chaos to rush-hour traffic with their calls for political change: thousands of protesters have taken to Belgrade's streets each evening since Prime Minister Aleksandar Vucic's presidential election win.
With no clear leader and claiming to be self-organised through Facebook, members of the crowd -- many of them students -- blow whistles and chant slogans against the premier, who won a landslide victory on April 2 to become head of state.
"Vucic thief, you stole the elections!" they shout, carrying placards reading "Against the government terror" and "Down with dictatorship".
As the protesters march, a few thousand strong, police cars frantically dart around the city trying to work out their route and divert oncoming traffic.
Although Vucic secured 55 percent of the vote in the face of a fractured opposition, the demonstrators say the poll was unfair and accuse him of becoming increasingly authoritarian.
Their rallies have spread to smaller cities, giving voice to more general grievances over the state of democracy and living standards in Serbia.
"We want to show that we are not passive, that we are not the Coca-Cola generation and that our voice counts," said Mima, a 21-year-old student who declined to give her surname, as she marched in Belgrade with friends.
The youngsters have been joined by protesters of all ages -- including parents who, in the 1990s, were among the hundreds of thousands of students who marched against Serbian strongman Slobodan Milosevic.
Marina Makovic, 39, said she wanted to "finish what we started at the time, which has not been completed".
Another female protester carried the sign: "Only 90s kids remember this."
- Vucic everywhere -
A former ultranationalist who served as information minister under Milosevic, Vucic has restyled himself as a pro-European reformist since he became prime minister in 2014.
But critics accuse the 47-year-old, who is omnipresent in television news programmes and daily papers, of clamping down on media freedom.
According to one survey he was given 51 percent of media space during the presidential campaign, while the rest was divided between 10 opposition candidates.
"I want the rule of law. Here one man occupies all the power, said 78-year-old Gorica Stanojcic, who said she was joining the protests "to support these kids, to help them fight for the right thing".
Some of Vucic's rivals have supported the protests, but demonstrators who spoke to AFP expressed a general distrust for "parasite" politicians as well as disappointment at the lack of a united opposition.
"All of them are corrupt," said one of the marchers, 24-year-old philosophy student Andreja.
"We want a state that could be part of a normal, European society," he said, expressing hope that the protests would last until change comes.
But differences within the protest movement are evident, with another marcher carrying an anti-European Union sign.
- Lacking leadership -
Andreja and his friends carried a huge banner at the front row of the crowd, bearing general demands such as "free and fair elections, press freedom, depoliticisation of institutions and public companies, and improved workers' rights".
Various trade unions, journalists associations and even some police and army unions have added their support to the main demands.
Cedomir Antic, a student leader from the 1990s rallies, said the demands "make sense" but were unlikely to be achieved without clear leadership for the protests.
The crowds are far from the game-changing numbers that toppled Milosevic, but analyst Aleksandar Popov says their intensity remains strong.
"There is huge discontent with the material situation and lack of freedoms, and people see that large amounts of (taxpayers') money were spent to enable one man to win the election," said Popov, who heads the Centre for Regionalism, a Serbian democracy group.
Washington-based Freedom House said in a 2017 report that Serbia's democracy score had dropped to its lowest level since 2005.
"While improvements were visible in some areas related to European Union accession, they were offset by negative developments in electoral process, democratic governance, and media freedom," it said.
Vucic himself, who is set to take over the presidency at the end of May, has said people have "a right to be unhappy with the election results" -- so long as their protests are "peaceful".
But he also accused opposition leaders, in particularly ex-ombudsman Sasa Jankovic who came second with 16 percent of vote, of being behind the protests. Jankovic denies this.
"You will solve nothing in the street," Vucic said, accusing his opponents of wanting "to introduce dictatorship in Serbia".