The foibe massacres (massacri delle foibe; poboji v fojbah; masakri fojbe), or simply the foibe, refers to mass killings and deportations both during and immediately after World War II, mainly committed by Yugoslav Partisans and OZNA in the then-Italian territories of Julian March (Karst Region and Istria), Kvarner and Dalmatia, against the local ethnic Italian population (Istrian Italians and Dalmatian Italians), as well as local Slavs and Istro-Romanians who chose to maintain Italian citizenship, opposing Yugoslav annexation.
There is academic consensus that these attacks were reprisal killings, after decades of fascist repression, forced Italianization and Italian war crimes against Yugoslavs. In addition, some historians also describe them as state terrorism and ethnic cleansing against Italians, including Italian anti-fascist militias and civilians. Other historians dispute this, arguing that Italians were not targeted for their ethnicity, that the majority of victims were members of fascist military and police forces, and that many more Slavic collaborators were killed in postwar reprisals. Among the victims were those opposed to the Yugoslav annexation of territories, killed as a preventive purge of real, potential or presumed opponents of Titoism, native anti-fascist autonomists — including the leadership of Italian anti-fascist partisan organizations, opposed to Yugoslav annexation, and the leaders of Fiume's Autonomist Party, like Mario Blasich and Nevio Skull, who supported local independence from both Italy and Yugoslavia — for example the purge in the city of Fiume, where at least 650 were killed during and after the war by Yugoslav units, not always judged before military courts.
The estimated number of people killed in the foibe is disputed, varying from hundreds to thousands, according to some sources 11,000 or 20,000. The Italian historian, Raoul Pupo estimates 3,000 to 4,000 total victims, across all areas of former Yugoslavia and Italy from 1943 to 1945, He places the events in the broader context of "the collapse of a structure of power and oppression: that of the fascist state in 1943, that of the Nazi-fascist state of the Adriatic coast in 1945.