Police chief Vladimir Faber and his chief of staff Stipo Rimac told a press conference on Saturday that two men, both Croatian nationals, were suspected of committing the murders.
The first suspect is a 44-year-old man from the nearby village of Cepin and the second one is a 33-year-old man from Djakovo, about 40 kilometres southwest of Osijek.
The first suspect is already in the custody of the Osijek Police Department while the second one was arrested by police in the Dubrovnik area on Friday and will be brought to the Osijek County Court's investigative centre later in the day.
There are reasonable grounds for suspicion that on 23 November 1991 the first suspect, who at the time served as deputy company commander within the Croatian Army 130th Brigade, shot dead Stevan and Dragica Gvozdenovic, husband and wife, and their relative, Ljubomir Grandic, for intimidation purposes and out of revenge, police said.
The two suspects are also alleged to have murdered one Savo Pavitovic, of Osijek, on 25 November 1991.