Stevan Vranesevic and Mirjana Djergovic appealed the decisions on their detention and the decisions sentencing them to prison.
A three-judge panel dismissed the appeals against the detention decisions as unfounded, making them final, said court president Zoran Potocki, adding the panel accepted the Zagreb Magistrate's Court's stance that if set free, the convicts might repeat the misdemeanor.
Potocki said his court did not decide about the appeals against the sentences because the other side in the proceedings, the Zagreb Police, also had the right to appeal but had not done so yet.
Zagreb Police spokeswoman Gordana Vulama told Hina the police would not appeal the sentences.
Three Serbian students were arrested in Zagreb's central square on Saturday afternoon after two of them, 24-year-old women, photographed 25-year-old Vranesic with a picture of Mihailovic, a convicted WWII criminal, in his hands. Some disgruntled citizens who saw this reported them to the police, after which the three students were arrested.
On Sunday, Zagreb's Magistrate's Court sentenced Vranesic to 15 and Djergovic, one of the women, to five days in jail, while the second woman was acquitted because it was not proved she had taken part in the offence.