Serbia on Friday banned Gay Pride for the third year running, saying the risk of allowing the parade to go ahead was too high.
The event had been scheduled for Saturday, but the prime minister announced that it would have to be cancelled after far-right groups threatened protests.
"Local police have decided to ban all gatherings scheduled for tomorrow (Saturday)," Prime Minister Ivica Dacic said.
"It could not currently be guaranteed that Gay Pride would pass off without incident," said Dacic, adding that both lives and property could have been jeopardised by the event.
It is the third time that Serbian authorities have banned Gay Pride at the eleventh hour, a sign of how divisive the issue remains in Serbia.
The 2010 event ended in violence that left more than 150 injured, mostly policemen, and caused damage estimated at more than one million euros ($1.35 million).
Before Friday's announcement, several far-right organisations had said they would protest on Saturday at the time when the parade was supposed to take place.
Organisers said the decision was a missed opportunity for Serbia to "prove that it is a country with the rule of law".
"This is pretty bad news for Serbia as it appears that human rights are not respected in the country," organiser Goran Miletic of the organisers told AFP.
Following the ban, a few hundred gay activists gathered before Serbian government building late on Friday carrying a huge banner that read "This is pride."
Escorted by dozens of policemen in anti-riot gear, the group then marched throughout downtown Belgrade to the Serbian parliament building, holding a huge flag in rainbow colours.
"We are not the ones who should be isolated nor the ones who should be removed from the street," Maja Micic of the organisers told reporters.
"We will have pride (parade) tonight and all 365 days until state institutions and this society are ready to deal properly with what we are talking about," she said.
Swedish Minister for European Union Affairs Birgitta Ohlsson, who was supposed to speak at the Saturday's event, expressed "disappointment" at the ban.
"This is a lost opportunity for the Serbian government to show that it is ready to fully respect human rights," Beta news agency quoted Ohlsson as saying.
The ban could hamper Serbia's EU membership talks that are expected to start by 2014.