BELGRADE (REUTERS) - Two Serbian men were jailed on Wednesday for the killing of a newspaper editor in neighbouring Croatia in 2008 whose political weekly had worked on exposing crime and corruption in the Balkans.

The Serbian verdict comes four years after six others were convicted in Croatia in 2010 and given lengthy sentences for involvement in the killing, but even now after both trials, investigators do not know who ordered the hit.

Zeljko Milovanovic was sentenced to 40 years by the Serbian court for planting explosive that killed Pukanic and another employee of the Nacional paper in downtown Zagreb.

Milenko Kuzmanovic was given five years for providing logistical support.

A third member of the group, Sreten Jocic, who prosecutors had said masterminded the murder of Nacional owner Ivo Pukanic, was released on lack of evidence.

Organised crime flourished in the Balkans during the wars that accompanied communist Yugoslavia's collapse in the 1990s.

Since then, all ex-Yugoslav republics have set their sights on joining the European Union, alongside members Slovenia and Croatia, and face pressure to tackle organised crime as a condition of integration.