Kramaric, who held a news conference in the coastal city of Pula on Monday, said that his policy as Osijek mayor was to call on citizens to refrain from doing anything they could be ashamed of after the war.
He stressed that there was no collective guilt and that nobody should take over the role of institutions or the police and the judiciary.
"Whenever I heard something about murders, I informed the state political leadership, from the head of state to the government, asking them to do something. In my capacity as mayor I could not take any steps on my own," Kramaric told the news conference.
He also criticised the current Serbian President Boris Tadic for his statement on the 1995 Croatian operation Storm.
The LS official said that "Operation Storm cannot be equated with Srebrenica".
Tadic has called on Croatian authorities to condemn crimes committed against Serbs during the August 1995 Operation Storm in the same manner in which he deplored crimes committed by Serb troops against Muslims in the Bosnian town of Srebrenica in July 1995.
Commenting on plans to unite the LS and the Croatian Social Liberal Party (HSLS), Kramaric said that the uniting of the two liberal parties had no alternative and that this should happen as soon as possible.