BELGRADE — Thousands of Serb demonstrators, chanting ‘‘Treason, Treason,’’ protested Monday against an agreement to normalize relations with breakaway Kosovo, a potentially landmark deal that could end years of tensions between the Balkan antagonists and put them both on a path to European Union membership.
Up to 10,000 flag-waving protesters gathered in the Kosovo town of Mitrovica, demanding that the EU-brokered agreement be annulled and branding the Serbian officials who endorsed it ‘‘traitors.’’
The Serbian government on Monday approved the deal unanimously at an extraordinary session and ordered ministries to implement it.
The prime ministers of Serbia and Kosovo reached a tentative deal in Brussels on Friday that would give Kosovo’s ethnic Albanian leadership authority over rebel Kosovo Serbs. In return, the minority Serbs would get wide autonomy within Kosovo.
After Serbia’s approval, the EU’s executive Commission recommended on Monday that the bloc start membership negotiations with Belgrade. The commission said in a report that ‘‘Serbia has taken very significant steps toward visible and sustainable improvement in relations with Kosovo.’’
‘‘This agreement is a huge step forward. It can mark a historic turning point for the two countries, but also for the entire region if it is implemented,’’ Foreign Minister Guido Westerwelle of Germany said.
Kosovo, which is considered by nationalists to be the cradle of the Serbian state and religion, declared independence in 2008. Serbia has vowed never to recognize it.