

Oliver Ivanović, a prominent Kosovo Serb politician, has been gunned down outside his party headquarters on the day that Belgrade and Pristina started talks on normalising ties after a break of more than a year.

Ivanović was shot six times by unknown assailants in a drive-by shooting in the divided city of Mitrovica. The popular former secretary of state for Kosovo and Metohija in the Serbian government was an opponent of the Belgrade-backed Serb party in Kosovo.

His death may further complicate the troubled relationship between Kosovo and Serbia, which continues to regard the region as a breakaway province. It also raises questions over international peacekeeping and rule-of-law missions in the region, which critics say turns a blind eye to organised crime.

Kosovo declared independence in 2008, and is recognised as an independent country by more than 100 countries, including the US, UK, and Germany. In 2013, the EU launched a new round of dialogue between Belgrade and Pristina, with Serbia offered candidacy for EU membership. Ethnic Serbs are a small but significant minority, while 90% of the population are ethnic Albanians.

Russia and Serbia, as well as several EU member states, do not recognise Kosovo’s independence, and Kosovo is not a member of the United Nations. Serb-dominated northern Kosovo remains under significant influence from Belgrade, and international diplomats are reportedly floating the idea of partition. Tensions over Kosovo were already mounting as the Pristina government moved to scrap a war crimes court that would try alleged offences committed by ethnic Albanians, possibly including members of the political elite.

In 2016, Ivanović was himself convicted of war crimes by a panel of international judges presiding over a Kosovo court. He was found guilty of ordering crimes against the civilian population in 1999 during the Kosovo war, which was brought to an end after an extensive Nato bombing campaign.

In February last year, the conviction was overturned and the case sent back for retrial. Violence has flared up in Kosovo several times since the end of the war, and Ivanović’s arrest in 2014 led to protests by ethnic Serbs in Kosovo, and strong objections from Belgrade. Ivanović pleaded not guilty, saying the prosecution was politically motivated.

Ivanović had warned about the security environment in Kosovo, requesting a more active stance by the EU’s rule of law mission in Kosovo, Eulex, and Kfor, the Nato-led peacekeeping force. One of Ivanović’s vehicles was burned outside his home in July in the run-up to local elections.

“Ivanović was a pragmatic moderate, eager to reach out to find a compromise that would improve the lives of all people in Mitrovica, north and [Albanian-dominated] south,” said a western diplomat, who asked not to be named. “But he was stained by the war crimes indictment. More needs to be done to tackle organised criminal structures in the north of Kosovo, including by Belgrade.”

Negotiations between officials representing Belgrade and Pristina in Brussels were due to restart on Tuesday, but the Serbian delegation withdrew after news of the murder. President Aleksandar Vučić convened a meeting of the council of national security at noon and is due to make a statement. A Belgrade government source told the Guardian that the delegation was also withdrawn due to recent sabre-rattling by Kosovo’s parliamentary speaker, Kadri Veseli.

“Whatever happens, it is likely that the murder will be used for political purposes,” said James Ker-Lindsay, a specialist in south-eastern Europe at St Mary’s University in London. “I suspect this will also be used by some to try to deflect attention away from the growing political tensions over the new Kosovo criminal court.”