BELGRADE, Serbia (AP) — Tens of thousands of opponents of Serbia's populist President Aleksandar Vucic rallied on Saturday in Serbia's capital Belgrade, backing up their demand for an early parliamentary election after nearly eight months of protests that have rattled his firm grip on power in the Balkan country.

Tensions have soared before the protest in Belgrade, which has been organized by Serbia's university students, a key force behind nationwide anti-corruption demonstrations that started after a renovated rail station canopy collapsed, killing 16 people on Nov. 1.

Many blamed the concrete roof crash on rampant government corruption and negligence in state infrastructure projects, leading to recurring mass protests.

Vucic and his right-wing Serbian Progressive Party have repeatedly refused the demand for an early vote and accused protesters of planning to spur violence on orders from abroad, which they didn't specify.

Vucic's authorities have launched a crackdown on Serbia's striking universities and other opponents, while increasing pressure on independent media as they tried to curb the demonstrations. The massive showing for Saturday's anti-Vucic rally, however, suggested that the resolve persists despite relentless pressure and after nearly eight months of almost daily protests.

Hours before the student-led rally, Vucic’s party bused in scores of its own supporters to Belgrade from other parts of the country, many wearing T-shirts reading: “We won’t give up Serbia.” They were joining a camp of Vucic’s loyalists in central Belgrade where they have been staying in tents since mid-March.

In a show of business as usual, Vucic handed out presidential awards in the capital to people he deemed worthy, including artists and journalists.

“People need not worry — the state will be defended and thugs brought to justice," Vucic told reporters on Saturday.

Serbian presidential and parliamentary elections are due in 2027.

Saturday marks St. Vitus Day, a religious holiday and the date when Serbs mark a 14th-century battle against Ottoman Turks in Kosovo that was the start of hundreds of years of Turkish rule, holding symbolic importance.

Earlier this week, police arrested several people accused of allegedly plotting to overthrow the government and banned entry into the country, without explanation, to several people from Croatia and a theater director from Montenegro.

Serbia's railway company halted train service over an alleged bomb threat in what critics said was an apparent bid to prevent people from traveling to Belgrade for the rally.

Authorities made similar moves back in March, before what was the biggest ever anti-government protest in the Balkan country, which drew hundreds of thousands of people.

Vucic’s loyalists then set up a camp in a park outside his office, which still stands. The otherwise peaceful gathering on March 15 came to an abrupt end when part of the crowd suddenly scattered in panic, triggering allegations that authorities used a sonic weapon against peaceful protesters — an accusation officials have denied.

Vucic, a former extreme nationalist, has become increasingly authoritarian since coming to power more than a decade ago. Though he formally says he wants Serbia to join the European Union, critics say Vucic has stifled democratic freedoms as he strengthened ties with Russia and China.