Thousands of Croatian far-right supporters have gathered in a field in southern Austria to commemorate the massacre of pro-Nazi Croats by communists at the end of World War II.

The controversial annual event was held Saturday near the village of Bleiburg. For Croatian nationalists, the site symbolizes their suffering under communism in the former Yugoslavia before they fought a war for independence in the 1990s.

Tens of thousands of Croatians, mostly pro-fascist soldiers, fled to Bleiburg in May 1945 amid a Yugoslav army offensive, only to be turned back from Austria by the British military and into the hands of anti-fascists. Thousands of the so-called Ustashas were killed in and around Bleiburg.

Austria's anti-fascist groups have held protests during the event.