Protesters seemed wanted to draw more attention to their rally by demonstrating on the eve of a key EU Balkan summit.
Slovenian police have clashed with anti-government protesters ahead of a major European Union summit.
Hundreds of demonstrators showed up to oppose the Slovenian government’s pandemic restrictions, the third rally in Ljubljana in a month.
Police fired tear gas and water cannon on Tuesday and a leader of the protest movement has reportedly been detained.
Officers also set up checkpoints and limited traffic around the capital city and at the venue where Wednesday’s EU summit will take place.
The protest was not directly linked to the summit, but protest leaders apparently sought the opportunity to get more media attention from foreign reporters covering the event.
EU leaders have been gathering in Ljubljana to discuss how to keep engaging with Western Balkans neighbours that hope to join the 27-nation bloc.
Slovenia - which currently holds the EU’s rotating presidency - introduced tough measures on COVID-19 passes last month.
Citizens are required to show that they are fully vaccinated or have recently tested negative for the virus to continue working in all state-run firms.
Slovenia has fully vaccinated nearly 48% of its population, a smaller share than in many other EU nations.