Those camps were set up in Begejci, Stajicevo, Sremska Mitrovica and Nis in Serbia and in Stara Gradiska when this Croatian town was under the control of Serb rebels supported by the then Yugoslav People's Army (JNA) during the 1991-1995 Homeland Defence War.
A statement issued by the Osijek prosecutors' office released only the initials and the years of the birth of the Serbian citizens charged with those war crimes.
Aleksandar Vasiljevic, who used to be the head of the JNA security department and Zivanovic, a JNA officer, were in charge of setting up those concentration camps.
The two men are in Serbia and are not within reach of Croatia's authorities, the Osijek office of the Chief State Prosecutor said adding that a warrant for their arrest has been issued.
According to testimonies made by people who had been detained in camps, some 30,000 people had passed through those camps, including 3,000 women and 500 children.
The Croatian prosecutorial authorities have obtained a portion of the documentation about JNA orders about the establishment of those detention camps from the International Criminal Tribunal for the former Yugoslavia (ICTY).
The Serbian prosecutorial authorities participated in the questioning of Vasiljevic in Belgrade, the Osijek office of the Chief State Prosecutor said.
The Croatian Commission for Missing Persons and Detainees has earlier reported that 7,666 people were exchanged from those camps between December 1991 to August 1992, including 219 juveniles, 932 women and 424 people above the age of 60; 46 per cent were civilians and 52 per cent soldiers, while the status of the rest was unidentified.
Former inmates have testified about murders they witnessed in those camps and about torture and mistreatment they experienced there.
"In all the prisons in Serbia, prisoners were subjected to mental and physical torture, without exception," the head of the above-mentioned Croatian commission, Ivan Grujic said .