A special ceremony is being held in Srebrenica as 520 newly identified victims of Europe's worst atrocity since World War II will finally be buried.

This anniversary will be the first time Bosnia mourns the massacre while knowing that the two alleged, leading perpetrators, Bosnian Serb commander Ratko Mladic and political leader Radovan Karadzic, are on trial before the UN war crimes court.

Watch video 01:32 Srebrenica in mourning

However, survivors and relatives of those killed in Srebrenica after Bosnian Serb forces overran the eastern Bosnian town on July 11, 1995, said the trials were too little, too late.

Among those taking part is Sevdija Halilovic, a woman in her fifties. Her father's remains were laid to rest in the mass funeral on Wednesday.

"My father's remains were exhumed from two mass graves. My two brothers were also killed in the massacre but have not been found yet," she told the AFP news agency. "It is the pain, an endless pain, and when July 11 arrives, every year, this pain becomes unbearable."

The Bosnian Serbs went to great lengths to hide the scale of the killings and returned months afterwards to dig up bodies from mass graves and put them in at least 28 so-called ‘secondary' grave sites. The excavations continue to this day.

Serbia's new President Tomislav Nikolic claimed last month that the killings constituted "grave war crimes" but not genocide. The EU's Commissioner for Home Affairs, Cecilia Malmstöm, offered a contrasting opinion on Twitter.

"Seventeen years after Genocide in Srebenica. Remembering the victims," Malmström wrote, signing her message with "/CM," denoting that she had written it, not a member of her staff.

jm/msh (Reuters, AP, AFP)