Serbian police have arrested several individuals accused of plotting to violently overthrow the government ahead of a major anti-government rally scheduled for June 28, the national holiday of Vidovdan, the interior ministry said.

Police detained six people on June 25 in multiple locations across the country, citing “grounds for suspicion” that they were preparing criminal acts against Serbia’s constitutional order. The arrests come just days before the planned June 28 protest in Belgrade, organised by student groups demanding early elections after months of mass anti-corruption demonstrations.

“Those arrested are suspected of planning violent change to the constitutional order and organising attacks on state institutions and pro-government media,” the Ministry of Internal Affairs (MUP) said in a statement. Authorities alleged the group met last week in a cafe in Kraljevo, central Serbia, to plot against the regime. 

State-run media later broadcast wiretapped conversations purportedly involving the suspects, including Ivan Matović, an opposition politician and entrepreneur from Kraljevo. Police said Matović was arrested on June 25 near Požega while carrying a CZ 765 pistol with a defaced serial number and 32 rounds of ammunition.

Also among those arrested is Branko “Majkan” Momčilović, a retired army officer and veteran of the Balkan wars of the 1990s. His home was searched on June 25, with authorities linking him to alleged plots targeting public order during the Vidovdan rally.

A 20-year-old university student, Stefan T., was also questioned this week after allegedly sharing messages in a WhatsApp group urging incursions into state institutions and media buildings during Saturday’s protest. The messages reportedly named specific targets, including Serbia’s Election Commission, Constitutional Court and the national broadcaster RTS.

Opposition groups have condemned the arrests as politically motivated. Hundreds gathered in central Belgrade on Thursday in protest, accusing the government of using security concerns to stifle dissent.

Vidovdan, which commemorates the 1389 Battle of Kosovo, is a symbolically charged date in Serbian history. It also marks the assassination of Archduke Franz Ferdinand in 1914, the 1948 split between Yugoslavia and Stalin’s Soviet Union and the extradition of former Yugoslav president Slobodan Milosevic to The Hague in 2001.

President Aleksandar Vucic, whose government has been the target of sustained protests since November 2024, said the state would respond “only if forced” during Saturday’s demonstration. “We will do everything to ensure no one is hurt,” he told reporters on June 26.

The ruling Serbian Progressive Party (SNS) maintains the protests are part of a broader attempt to incite unrest. SNS president Milos Vucevic described the arrests as proof of “an ongoing attempt at a colour revolution” — the favourite theme of the government — and vowed further action against what he called “attempts at a violent seizure of power”.

Authorities made similar arrests in March ahead of one of the largest anti-government protests in Serbia’s recent history. That gathering ended abruptly amid panic, as video footage suggests the government deployed crowd control technology, an allegation officials deny.

Student-led groups have been at the forefront of the demonstrations, sparked by a deadly infrastructure failure in November that killed 16 people and galvanised public anger over corruption and government accountability.

The June 28 rally is expected to draw thousands, with tensions running high amid accusations of government overreach and concerns about escalating political instability.