They have been protesting since October last year against the EU-brokered agreement with Serbia and have organized street protests, clashed with the police several times and last month set the government building on fire.
They have also frequently released tear gas in parliament over the last few months.
«We will stay here until the government goes home,» the president of the biggest opposition party Vetevendosje, Visar Ymeri, said as supporters around him set up red and green tents in front of the main government building.
«Kosovo cannot be governed by politicians who have endangered the country’s sovereignty,» he said.
Last Friday, the opposition released tear gas in parliament to protest against the deal with Serbia and to demand the cancellation of a border deal with Montenegro.
Opposition politicians release tear gas in parliament to obstruct a session in Pristina, Kosovo, Feb. 19, 2016.
The government says opposition party leaders are provoking violence and trying to drag Kosovo into «crime and anarchy.»
Kosovo declared independence from Serbia in 2008, almost a decade after NATO airstrikes drove out Serbian security forces accused of killing and expelling ethnic Albanian civilians during a counter-insurgency war.
Many Kosovo Albanians believe last year’s accord with Serbia represents a threat to that hard-won sovereignty, though its status is unclear after the constitutional court ruled in December that parts of it breach the country’s laws.