Kosovo police have used tear gas and pepper spray to break up a protest in the capital, Pristina, by stone-throwing nationalists opposed to European Union-mediated talks with Serbia.

Authorities said Monday's confrontation outside government headquarters injured at least 18 police officers and several demonstrators. Police briefly detained several lawmakers of the ultranationalist Self Determination party who joined the protest.

The nationalist demonstrators denounced Kosovo Prime Minister Hashim Thaci for meeting with Serbian Prime Minister Ivica Dacic last Friday in Brussels, where EU foreign policy chief Catherine Ashton acted as a mediator. It was the highest-level meeting between the two sides since Kosovo seceded from Serbia in a 2008 move rejected by Belgrade.

Self Determination party members said it was shameful and criminal for Mr. Thaci to engage in talks with Serbia, which they said refuses to apologize for waging a two-year war against ethnic Albanian separatists in Kosovo in the 1990s. A NATO bombing campaign pressured Serbia into stopping the offensive in 1999.

The Thaci-Dacic meeting was aimed at easing tensions between Kosovo and Serbia and helping them to achieve their aspiration of joining the 27-nation EU bloc. Belgrade already has earned EU candidate status, but Brussels has told both sides to make progress in normalizing their relations before proceeding with their EU membership bids.

Kosovo is recognized as an independent state by around 90 nations, 22 of them from the EU. But five EU members refuse to grant recognition to Pristina. Belgrade insists that Kosovo remains a Serbian province.