ROME, Jan. 23 (Xinhua) -- Italian fugitives who escaped abroad to avoid sentences in Italy should all be returned to the country, Italian President Sergio Mattarella said on Wednesday.

He made the remarks at a ceremony marking the 40th anniversary of the killing of trade unionist Guido Rossa, who was murdered by Italian leftist terrorist group Red Brigades in 1979 in northwest Genoa city.

"Along with his family, he paid a supreme price for standing by the values of the Republic," Mattarella told an audience of top officials gathered for the ceremony.

Thanks to its social cohesion, he explained, the Italian state was able to overcome that period of social turmoil and political violence stretching from 1969 to the early 1980s.

Those years, also dubbed the "Years of Lead", were marked by frequent political clashes and terrorist acts from both leftist and far-right groups that claimed over 400 victims including former Prime Minister Aldo Moro.

According to the president, Italy "passed the test" at the time due to the foresight of its government officials, and to the commitment of police, judiciary, unions, and other key social actors to justice.

While hundreds of militants were arrested and held accountable for their acts, dozens from both leftist and far-right groups, however, were able to find refuge abroad, in France, UK, Latin American countries, Japan and elsewhere.

"Some decades later, that commitment (to justice) cannot be considered as fully accomplished," Mattarella stressed in his address.

"A definite closure of that period requires that justice is fully accomplished, and all those who were found guilty of serious crimes and escaped their sentences give their testimony and face their punishment," he added.

The debate over Italian fugitives from the Years of Lead re-emerged recently here, after the capture and extradition to Italy of former left-wing militant Cesare Battisti.

The man, a 64-year former member of far-left group Armed Proletarians for Communism in the 1970s, was captured in Bolivia earlier this month after 38 years on the run.

Battisti had already taken refuge in France (twice), Mexico, and Brazil, since breaking out of an Italian jail in 1981. He had a life sentence to serve for being involved in four killings.

After his extradition, Italian Interior Minister Matteo Salvini repeatedly urged France to extradite other far-left militants who have also found refuge there for decades to avoid judicial sentences.

At least 30 convicted fugitives would in fact remain at large, 14 of them in France, Italian media reported last week citing sources from the Interior Ministry.

"The Italian government is ready to take all the necessary official steps to ask for the cooperation of those countries hosting fugitives, starting with France," La Stampa newspaper wrote.