Unfortunately, things like this have been with us for at least six thousand years.  Just since the end of the Soviet Union there have been multiple incidents in the Balkans, where such massacres have been common throughout most of history.  Communist Yugoslavia under Tito was forced to keep ethnic tensions in check.  With that restraint gone, all broke loose, including tensions dating back to the centuries of Turkish domination.  Bosnians, Serba and Croats are the same ethnic group with the same language, but Croats are largely Roman Catholic, Serbs Othodox, and Bosnians tend to be Muslim. The same territorial and religious disputes that erupted into war in 1914 are unresolved in the Balkans to this day.

In the former Soviet Union itself the Chechen wars have resulted in accusations of genocide.  The Chechen people resisted Russian invasion in the 18th century, and sided with the Red Army in the Civil War after 1917.  But in 1943 Stalin had the entire population packed up over two nights and put on trains to Siberia.  Approximately half the Chechens died on the trip or during the winter of 1943-44.  Since the fall of the USSR tensions have run high in Chechnya, with open warfare and the massacre of civilians involved.

Sadly, these are only two examples of the wars like this taking place all over the world right now, and the many similar places in a lull between outbreaks.