Police in Serbia have arrested six individuals suspected of planning criminal acts against the constitutional order and security of Serbia.

The arrests come as tensions mount ahead of an anti-corruption rally scheduled for this weekend in Belgrade.

Additionally, another university student was apprehended earlier in the week for allegedly preparing an act of terrorism based on private mobile phone conversations.

This has sparked a demonstration by hundreds in Belgrade protesting these actions.

University students have been at the forefront of nearly eight months of protests against corruption and are demanding early elections.

These demonstrations began after a rail station canopy collapse in November, resulting in 16 fatalities and widespread accusations of government negligence and corruption.

President Aleksandar Vucic and his Serbian Progressive Party have rejected the demand for an early vote and instead accused the protesters of planning violence at Saturday's rally.

The detained group is said to have met last week in a hotel in Kraljevo, with police claiming that one of the suspects possessed a gun and ammunition.

Other details regarding those arrested remain unclear.

This comes after similar arrests were made in March ahead of what was described as the largest anti-government protest in Serbia's history, which drew hundreds of thousands.

Vucic has been criticized for his increasing authoritarian tendencies and strained democratic freedoms since coming to power over a decade ago, despite officially supporting Serbia's EU accession.

His government has strengthened ties with Russia and China, further fueling dissent.