Turin, Italy  - Italian President Giorgio Napolitano on Thursday defended Israel's right to exist at the opening of the 2008 Turin International Book Fair which has chosen the Jewish state as "guest country".

"There is no dialogue if one moves from a rejection of the state of Israel's legitimacy and its right to exist in peace and security," Napolitano said.

Minutes before Napolitano was scheduled to speak, security guards at Turin's Lingotto complex which hosts the Book Fair, prevented a group of protestors from unfurling a banner criticizing "Zionist Colonialism".

Controversy has raged around this year's edition of the annual event since organizers named as guest country Israel, which this year celebrates the 60th anniversary of its birth.

Leftist groups allege that the Book Fair's organizers, including Turin's centre-left city government, are ignoring what the leftists say is Israel's repression of the Palestinian people.

At a May 1 worker's day rally in Turin last week, protestors calling for a boycott of the Book Fair set fire to Israeli flags.

The incident has prompted authorities to tighten security and to deploy hundreds of police.

Authorities have also declared the Lingotto out of bounds for leftist protestors who have scheduled a street parade for Saturday to protest against Israel's presence at the Book Fair. (dpa)