Bosnian Muslims and Iraqi religious minority Yazidis have mourned together, both calling for atrocities committed against their people to be recognised as genocide.
The Yazidis were seeking recognition and prosecution of those responsible for the 2014 killing of thousands of Yazidis by Islamic State militants. Some Yazidis were buried alive. Thousands of women were taken as slaves. It has been called a genocide by a UN commission.
Bosnian Muslims were commemorating the massacre of 8000 men and boys killed in 1995 at Srebrenica by Bosnian Serb forces. The massacre was called a genocide by two United Nations courts and leaders including General Ratko Mladic have been prosecuted at the UN war crimes tribunal in The Hague.
"We have endured horrific abuse and persecution - the Bosnian Muslims at the hands of Serbs and Yazidis at the hands of the Islamic State (IS) - and we share the memories and recognise each others' feelings," said Hussam Abdukah, a Yazidi lawyer who is documenting the IS crimes and is a member of a peacebuilding programme in northern Iraq.
Tuesday's commemoration of the killings at Srebrenica 22 years ago included the burials of 71 newly identified victims at a cemetery near the eastern town, bringing the total number interred there to 6575.
More than 1000 men and boys are still missing. The Serb forces dumped the victims' bodies in pits and subsequently dug them up and scattered them in a systematic effort to conceal the crime, Europe's worst atrocity since World War Two.
Yazidis will commemorate the Sinjar massacre in August.
The activists attending the Srebrenica anniversary, who also included two Iraqis, said they hoped to use the Srebrenica families' experiences to help build cases against IS fighters that can eventually be used in international criminal courts.
"We urge the international community that just like in Srebrenica it helps open mass graves and build cases because we fear that traces of the crime might stay hidden," said Basma Naji, who fled Sinjar just hours before the attack.
Bosnian Serb wartime leader Radovan Karadzic was jailed last year for 40 years by The Hague tribunal while his military chief Mladic is still being tried on genocide charges.
Dozens of Bosnian Serb lower-ranking officials were jailed over the Srebrenica atrocity by the Bosnian war crimes court.
Most Serbs strongly deny the massacre was genocide, however, and regard Karadzic and Mladic as national heroes. That divide continues to hinder reconciliation and stifle Bosnia's progress towards integration with Western Europe.
Among those buried on Tuesday was Munib Salkic, who was 15 when he was killed at Srebrenica.
"For more than 20 years I had hoped my brother was alive," his sister Emina Kuranovic said through tears beside a green-draped coffin holding Salkic's remains.
"I did not believe that anybody could have killed a child."