Italy marks Giorno del Ricordo on 10 February.
Italy on Friday commemorates the victims of the Foibe mass killings in Friuli-Venezia Giulia, Istria and Dalmatia by Tito's partisans, both during and after world war two.
The massacres were committed mainly against the local ethnic Italian population by Yugoslav communists who occupied the Istrian peninsula during the last two years of the war.
To mark the solemn occasion, the façade of the government buildings at Palazzo Chigi in Rome will be illuminated with the colours of the Italian flag
, with the words "Io Ricordo" (I Remember), from 18.00 on Friday until dawn on Saturday.
Italian culture minister Gennaro Sanguiliano
requested the organisers of Sanremo
, Italy's biggest music festival, to use the stage on Friday night to remember the victims of the Foibe.
Addressing the Italian parliament on Wednesday, the speaker for the lower house Lorenzo Fontana
described the Foibe massacres as "one of the darkest and most horrific pages in history".
Last year Italian president Sergio Mattarella said the Giorno del Ricordo calls for the "recollection and solidarity with the relatives and descendants of those who were cruelly killed and thrown into the Foibe, of the Italians torn from their homes and forced into exodus, of all those on the eastern border who had to pay the highest human costs to the horrors of the second world war and its prolonging of the persecution, violent nationalism, oppressive totalitarianism."
The exact number of victims is unknown but there may have been up to 15,000 killed, with many of them tortured, shot or pushed to their deaths into the deep, narrow carsic sinkholes or chasms known as foibe.
The killings occurred in 1943 and again in the weeks before and after the end of the war in 1945.
The Giorno del Ricordo commemorates the victims of the ethnic cleansing as well as the exodus of Italians who left their homes in Dalmatia and Istria in the years after 1943.
Three years ago Mattarella joined Slovenian president Borut Pahor in laying a wreath at a Foibe memorial in Basovizza near the north Italian city of Trieste.
Known in English as the 'National Memorial Day of the Exiles and Foibe', the annual remembrance day was declared in 2004 by then Italian president Carlo Azeglio Ciampi.
In 2007 Ciampi's successor, President Giorgio Napolitano, referred to the Foibe as "one of the barbarities of the past century."