Zagreb - Prime Minister Ivo Sanader's conservative Croatian Democratic Union (HDZ) suffered a major setback in local elections, losing out to the opposition in vying for key mayoral posts, media reports said Monday.

While the HDZ did fairly well in the run for local councils, it lost virtually all major mayoral races in Sunday's poll. "HDZ became a villages and country party," headlines said.

Zagreb and the key Adriatic port of Rijeka went to the opposition Social Democratic Party, while independent runner, billionaire Zeljko Kerum, was elected mayor of Split, another major port.

In Osijek, in eastern Croatia, most votes went to the party of lawmaker and convicted war criminal, Branimir Glavas.

The former Croatian army major fled to Bosnia in May after receiving a 10-year sentence for the murder and torture of Serbs in Osijek nearly two decades ago. (dpa)