Masked assailants have broken windows and thrown a petrol bomb at the office of Kosovo's president but failed to set fire to the building, police say.
No one has claimed responsibility for the 4am attack on Saturday in the centre of the capital Pristina.
The government has condemned the attack as "dangerous for the constitutional order and the country's stability".
Kosovo is facing a political crisis, with the opposition denouncing an EU-brokered deal with Serbia to give more rights to local Serbs.
The issue is highly emotive, eight years after Kosovo declared independence from Belgrade and less than two decades after a war that drew in NATO.
"Masked people have hurled a petrol bomb at the president's office," the police said in a statement. "They broke the window with stones but failed to throw the petrol bomb inside and the bottle hit the wall."
The office was empty at the time and no one was injured.
Part of a wall facing a busy road was blackened by smoke from the burning petrol.
The office is used by outgoing President Atifete Jahjaga and will be taken over by newly elected President Hashim Thaci next month.
Opposition lawmakers, angry at the deal with Serbia, released teargas in Kosovo's parliament and protesters outside threw petrol bombs in an unsuccessful attempt to block Thaci's election last month.
The opposition, which is demanding the resignation of the government and a snap election, has denied it is behind these attacks. They have called fresh protests on March 26.
Kosovo declared independence in 2008, almost a decade after NATO air strikes drove out Serbian security forces accused of killing and expelling ethnic Albanian civilians during a counter-insurgency war.