People gather at the Potocari Memorial Centre in the suburbs of Srebrenica, Bosnia, on Sunday. (Marko Drobnjakovic/Associated Press)

Tens of thousands gathered Sunday in the eastern Bosnian town of Srebrenica to bury hundreds of massacre victims on the 15th anniversary of the worst crime in Europe since the Nazi era.

A whole hillside was dug out with graves waiting for 775 coffins to be laid to rest at the biggest Srebrenica funeral so far. Still, that was less than a 10th of the total number of Muslim men and boys executed after Serb forces overran the UN-protected town on July 11, 1995, during the 1992-1995 Bosnian war.

A grieving Bosnian woman is comforted near the coffin of her relative, a victim of the 1995 Srebrenica massacre, during Sunday's ceremony. (Amel Emric/Associated Press)

At the time, some 30,000 Bosnian Muslims had flocked to the UN military base in the town's suburb of Potocari for refuge. But when Serb forces came, they outnumbered Dutch troops and were able to break through UN defences. The Serbs separated out men and boys, taking them away on vehicles, the vast majority never to be seen again.

The Srebrenica memorial centre now stands across the road from that former UN base. The bodies being buried Sunday were previously excavated from mass graves and identified through DNA tests.

An estimated 60,000 people were at the memorial Sunday. Relatives mingled among the pits on one side and rows of green coffins on the other, looking for the names of their loved ones. Muslim prayers and weeping mixed with speeches of dignitaries condemning the crimes and calling for the perpetrators to be punished.

Serbian president attends as 'act of reconciliation'

Fifteen years later, no one represented the UN at the ceremony. Serbian President Boris Tadic was the first dignitary to arrive, saying he was coming in an "act of reconciliation."

He wanted to "build bridges of trust and understanding among the nations in the region," he said in Belgrade.

In Srebrenica, some in the crowd yelled "Bravo, Boris!" while others asked "Where is Mladic?" — a reference to former Bosnian Serb general Ratko Mladic, who led the Serb troops into Srebrenica.

"I wish to welcome you. We are receiving you in peace," said Kada Hotic, a representative of the Srebrenica widows, while Tadic held both of her hands.

Serbian President Boris Tadic, centre, pays his respect to the Srebrenica victims at the Potocari Memorial Centre. (Marko Drobnjakovic/Associated Press)

Mladic and former Bosnian Serb president Radovan Karadzic were indicted on genocide charges by a UN war crimes tribunal in 1995. Karadzic is now on trial at the tribunal in The Hague while Mladic is still a fugitive, presumably hiding in Serbia.

Tadic said in a short statement that he "will do everything" to apprehend all war crimes suspects in Serbia.

The U.S. ambassador to Bosnia, Charles English, read a message from President Barack Obama that urged "governments to redouble their efforts" and arrest those responsible for the war crimes at Srebrenica.

Obama called the Srebrenica genocide a "stain on our collective consciousness" that occurred even after decades of pledges of "never again" after Nazi atrocities during the Second World War.

Bosnian Serbs sent no representatives to Sunday's ceremony. In a deliberate snub, Karadzic's Serb Democratic Party honoured him Saturday at a ceremony marking the 20th anniversary of the party's founding.

Despite the stirring speeches Sunday by politicians, many of those crying and hugging coffins were not really listening. Two sisters, Amela and Bahrija, sat stonefaced next to pit number 495 holding each other's hands and not responding even to the questions of their husbands.

They came to bury their father, Ejup Golic, who was 56 when he was killed.

All but one of the victims buried Sunday were Muslims. Rudolf Hren's grave will so far be the only one marked with a Catholic cross.

"They asked me if I wanted him to be buried elsewhere because this is mainly a Muslim graveyard," said his mother, Barbara Hren. "He died with them. Let him rest with them."