TEHRAN: Religious extremism has become "a weapon of mass destruction," former Irish president Mary Robinson told a conference in Iran on ''Religion in the Modern World'' on Monday.

Robinson called for a strengthening of "dialogue among political and religious leaders to prevent conflict and tension in the world."

She urged "respect towards religious minorities", warning against "religious extremism, which has become a weapon of mass destruction."

The two-day meeting of Western former leaders is being hosted by former Iranian president Mohammad Khatami amid speculation he might stand for office again.

The event has been organised by the Foundation for Dialogue among Civilisations, headed by Khatami, the Oslo Centre for Peace and Human Rights, and the Club de Madrid, which brings together former prime ministers and presidents.

The organisers denied any links between the event and the ex-president''s possible plans for candidacy.

"We should not spoil this conference with such matters," said Khatami, who pursued a policy of detente with the West during his 1997-2005 presidency.

Other participants also spoke out against extremism.

Former Norwegian prime minister Kejll Magne Bondevik denounced statements such as "Israel should be wiped off the map", which Khatami''s successor President Mahmoud Ahmadinejad said shortly after his 2005 election.

She also denounced the term "axis of evil" that US President George W. Bush used in reference to Iran, Saddam Hussein''s Iraq and North Korea.

Former UN chief Kofi Annan hit out at "opportunistic politicians who make extremist speeches to get elected."

Other participants included former Italian prime minister Romano Prodi, French ex-prime minister Lionel Jospin, Portuguese ex-president Jorge Sampaio and Swiss ex-president Joseph Deiss.

Western officials have shied away from visiting Iran since the election of Ahmadinejad, who has infuriated the international community with his repeated verbal attacks on Israel.

Participants maintained that the gathering was not political and that it sought to improve dialogue among different cultures with a focus on religion.