Protesters flood Belgrade in one of biggest anti-government rallies

More than 100,000 protesters descended on Serbia's capital Belgrade on Saturday in one of the largest rallies in decades, with students and workers facing riot police and supporters of President Aleksandar Vucic.

Serbia has seen months of anti-government rallies after 15 deaths from a railway station roof collapse triggered accusations of widespread corruption and negligence.

The protests have swelled to include students, teachers and farmers in a major challenge to Vucic, a populist in power for 12 years as prime minister or president.

"We will not allow you to deprive us of our freedoms," one student said in a series of speeches from a stage.

A security source and witnesses estimated the crowd at well over 100,000 people.

The government denies accusations of graft and incompetence and says Western intelligence agencies are backing a push to destabilise Serbia.

Though the protests have been largely peaceful, police said a car rammed a column of protesters, injuring three people, in a Belgrade suburb, while a group of men attacked and injured a student and university lecture in the centre.

Police said they apprehended 13 people in incidents overnight and early on Saturday, including three men after an attack on pro-Vucic farmers' tractors parked in a ring around Pionirski Park where government supporters have been camping.

FESTIVE MOOD

Across the street from the park, hundreds of veterans from elite military brigades in maroon berets and bikers, both allied with the students, lined up as the march proceeded between the parliament building and nearby Slavija square.

Students established their own security guards, clad in fluorescent yellow vests, between police and protesters.

"Today we will demonstrate our dissent ... to show what we are striving for, a normal state, a state of law, without corruption, lying, media pressures, persecutions," said Aleksa Cvetanovic, a 23 year-old student who has been attending demonstrations since December.

Streets were choked as protesters kept up a festive mood, lighting flares and chanting their slogan "Pump it up."

The students are demanding the release of documents about last year's railway station disaster in the city of Novi Sad, and accountability for those responsible.

Many had travelled hundreds of miles on foot or by bike.

Dozens of Belgrade residents took heaters outdoors for the protesters and offered them hot food. Grandmothers gave students freshly-baked biscuits and pies.

Prosecutors have charged 13 people over the Novi Sad disaster, and the government has announced an anti-corruption campaign. Prime Minister Milos Vucevic and two ministers have also resigned during the protests.

Saturday's protesters also called for a renewed general strike in coming days, though past appeals have failed to galvanise public service workers or many businesses.