Thousands of mourners have gathered to commemorate the 24th anniversary of the Srebrenica massacre, the worst mass killing in Europe since the Second World War, as Serbian officials continued to dispute that genocide was committed in the eastern Bosnian enclave.

Relatives of the more than 8,000 Bosnian Muslim men and boys killed by Bosnian Serb troops were among those attending a ceremony at a memorial site that included the burial of 33 newly identified victims of the killings that took place July 11-22 1995.

More than 1,000 are still considered missing from the mass slaughter during the Bosnian civil war.

Bosnia Srebrenica Anniversary
Women wait for the funeral ceremony (Darko Bandic/AP)

Many victims were ambushed along forest routes while fleeing Srebrenica in scorching heat without food or water.

They were either shot on the spot, or taken to collective centres where they were executed and thrown into mass graves.

Mevlid Halilovic, a relative of a victim, said many of the people who carried out the massacre were still at large.

“Those who did this (killing) have to be punished,” he said.

“And it was all done by our (Serb) neighbours, those who live just around here.”

Bosnia Srebrenica Anniversary
Fresh graves are dug at the memorial cemetery in Potocari near Srebrenica (Darko Bandic/AP)

Nura Begovic was burying the remains of her brother, who was identified through his hand bone.

“I spent 24 years looking for his body and I only found one bone,” she said.

“But today, both I and my family have found peace.”

Both Bosnian Serb wartime leader Radovan Karadzic and military commander Ratko Mladic, who led troops that captured Srebrenica on July 11 1995, were sentenced by a UN war crimes court to life in prison.

Although the mass killings were branded genocide by international courts, Serbian and Bosnia Serb officials refuse to use the term.

They did not send official delegations to the commemoration on Thursday.

Bosnia Srebrenica Anniversary
Women pay their respects next to the vehicle carrying the remains of 33 victims of the Srebrenica massacre (Darko Bandic/AP)

Nenad Popovic, an openly pro-Russian minister in Serbia’s government, said in a statement that “there was no genocide in Srebrenica and Serbs will never accept to be stamped as genocidal people”.

He said Serbia should rethink its goal of becoming a European Union member because of such claims.

Western officials disagreed.

“Today marks the passage of 24 years since the genocide in Srebrenica,” US secretary of state Mike Pompeo said in a statement.

“This painful chapter in European history must never be denied nor forgotten. We stand with those who continue to seek justice.”

A joint statement issued by European Union foreign policy chief Federica Mogherini and EU enlargement commissioner Johannes Hahn, using the term “genocide”, called it “one of the darkest moments of humanity in modern European history”.

“There is no place for inflammatory rhetoric, for denial, revisionism or the glorification of war criminals,” the statement said.

“Attempts to rewrite history in Bosnia and Herzegovina or anywhere are unacceptable.”