During the peacefully protest with about 10 policemen deployed as security, the protesters carried banners with slogans such as "Crime with Impunity" or "Croatia still hides 2,650 murdered Krajina Serbs" and displayed a list with names and photographs of their family members who were killed or disappeared during that operation of Croatian armed forces and police.
Protesters read out an open letter which they would send to the Croatian parliament, president and prime minister.
The letter reads that they ask for the re-introduction of their equal status in the Croatian Constitution, and measures for enabling Serbs to get jobs, resolve their tenancy rights and pensions more easily than so far.
The demonstrators said that 12 years had passed since Operation Storm, but little headway had been made in shedding more light on the fate of the missing people.
Serbian Prime Minister Vojislav Kostunica has issued a statement in which he branded Operation Storm as an action aimed at cleansing Serbs from Croatia.
According to the statement published by the Serbian Government, Kostunica said that the Serb people would never forget "horrendous scenes" of ethnic cleansing in August 1995 when Krajina Serbs were forced to leave their homes.
"It is our duty to pay tribute, as a people, to all innocent Serb casualties in Operation Storm," he said.