It's a national holiday commemorating the day in 1994 when the killing stopped, marking the end of a 100-day genocide that left nearly a million Rwandans dead.
The U.N. endorsed the "Responsibility to Protect" doctrine in 2005, calling on world powers to stop atrocities. But the secretary general says there's no longer global solidarity on the agreement.
German legislators overwhelmingly agreed the World War I-era killing of up to 1.5 million Armenians by Ottoman Turks constituted genocide. In response, Turkey withdrew its ambassador to Germany.
It has been 20 years since the massacre at Srebrenica, Bosnia, when some 8,000 Bosnian men and boys died or went missing. Bosnian-Americans now living in Missouri can't escape the memories.
Serbian Prime Minister Aleksandar Vucic, who was attending a ceremony in Bosnia and Herzegovina to mark the 1995 massacre, was driven away by a crowd throwing rocks and bottles.
The conflict that followed the breakup of Yugoslavia in the early 1990s included widespread violence, says the International Court of Justice. But it adds that the violence can't be deemed genocide.
Polish lawyer Raphael Lemkin coined the word in 1943, as part of his lifelong campaign to make the world acknowledge and prosecute the crime. A new documentary, Watchers of the Sky, tells his story.