Oliver Ivanovic, a prominent Kosovo Serb politician, has been shot dead outside his party offices in the Serb-run north of Mitrovica.
Several shots were fired at Ivanovic, seen as one of the more moderate Kosovo Serb leaders, Reports say.
Ethnic Albanians run the south of Mitrovica.
In January 2016, EU judges in Kosovo sentenced him to nine years for alleged war crimes committed in 1999, reports BBC.
But in February 2017 an appeals court overruled them and ordered a retrial.
He headed a Kosovo Serb party called Freedom, Democracy, Justice.
TF