"This is a problem which must be solved at the top level between the two countries. Those are issues which cannot be the topic of talks of state prosecutorial authorities, as unclear agreements between the Croatian and the Serbian prosecutorial authorities have brought us to the point where we are now," Milanovic said at an election rally in the eastern town of Vukovar on Saturday.

"It is unbelievable that 20 years after the was indictments 20 years old are coming to us. This reflects a mess in the relevant agencies also in Serbia as well as unclear agreements and contracts between the two countries' prosecutorial authorities," the SDP chief said adding, however, that this is something which must be discussed by the top authorities rather than by state prosecutors.

He said that when it came to border demarcation Croatia must hold talks with Serbia and other neighbours and not behave like Slovenia which used this issue to blackmail Croatia.

Sending a message with best wishes on Croatia's Independence Day, Milanovic said that Croatia should be "a homeland that suits its citizens".

As for the current course of the campaign ahead of the forthcoming parliamentary elections, Milanovic said that there was much venom.

Milanovic and SDP officials presented the Agenda 21 of the coalition of the four opposition parties at the rally.

With regard to speculations about the dismissal of the bulk of employees in the state administration if the Opposition comes to power, the SDP chief rejected it as a lie spread by the Croatian Democratic Union (HDZ).