The protesters – who carried a massive Serbian flag – included groups that also shouted slogans backing Serbia’s long-term ally, Russia, as well as nationalistic and far-right causes.

A row of bikers who support the policies of Russian President Vladimir Putin and Russia’s invasion of Ukraine, revved their engines in support of the crowds that marched to Belgrade’s St Sava cathedral for prayers.

In a sermon, the head of the Serbian Orthodox Church, Patriarch Porfirije, said the EuroPride event threatened traditional family values.

“They want to desecrate the sanctity of marriage and the family, and impose an unnatural union as a substitute for marriage,” he told the crowd.

Serbia’s president, Aleksandar Vučić, said on Saturday there had been threats against the march, and it was up to the police whether it should be stopped.

LGBTQI and rights groups have repeatedly said they will march on Saturday even if authorities call it off.

Gay sex is decriminalised in Serbia, but same-sex marriages are not allowed, and activists say the LGBTQI community faces hostility and discrimination.

Serbian governments have banned Pride parades in the past, and some events in the early 2000s were marred by violence.

Many in Sunday’s crowd waved Russian flags, a show of support for Moscow in a country where the government is trying to balance its ambition to join the European Union with its longstanding ties with Russia and China.

Brussels has said Serbia needs to make a string of reforms to become an EU member, including improving the rule of law and its human and minority rights record.

(Reporting by Fedja Grulovic; Writing by Aleksandar Vasovic; Editing by Andrew Heavens.)