Pope Benedict XVI yesterday ventured into the heartland of Italian organised crime, urging the young people of Naples to escape the clutches of the Camorra, the Naples version of the Mafia.

Opening a three day multi-faith meeting with an open air mass in Naples, the Pope called for a "struggle against all forms of violence". Graffiti on the walls had threatened "Death to Ratzinger" and "Hang the Pope" ahead of the visit, and security was tight, with the streets of Naples cleared of rubbish and closed to traffic.

The pontiff also braved icy temperatures, high winds and driving rain, with pilgrims on Piazza del Plebiscito, the city's main cobbled square in front of the Bourbon-era Royal Palace, wearing cellophane macs handed out by stewards and huddling under umbrellas. The German-born pontiff's voice appeared hoarse at times.

Before meeting Muslim, Jewish, Hindu and Buddhist leaders as well as Anglican and Orthodox Christians Pope Benedict - the first Pope to visit Naples since John Paul II in 1990 - deplored "the sad phenomenon of violence.....It is not only a matter of the deplorable number of crimes of the Camorra, but also of the fact that violence tends unfortunately to become a widespread mentality, insinuating itself into the fabric of society."

He acknowledged that Naples "does not lack healthy energy and good, culturally adept people with a strong sense of family". But he added: "For many, life is not simple. There are so many situations of poverty, poor housing, unemployment and underemployment, and a lack of future prospects." He called for "intensified efforts for a serious strategy of prevention centring on schools, work and helping young people to manage their free time."

The inter faith meeting on "A World without Violence", organised by the community of Sant'Egidio, a Vatican-linked body, is being attended by Dr Rowan Williams, the Archbishop of Canterbury, the Orthodox Ecumenical Patriarch of Constantinople, Bartholomew I, Israel's chief rabbi Yona Metzger, the imam of the United Arab Emirates, Ibrahim Ezzeddin, and Ayatollah Sayed Mohammad Mousavi Bojnourdi, head of an Islamic study centre in Iran.

The Pope did not however refer to a letter sent to him earlier this month October by 138 Muslim scholars and leaders appealing for dialogue on common elements in Islam and Christianity. Dr Williams, who is today addressing the meeting on the role of scripture - above all the Bible and the Koran - in faith dialogue, said there was an urgent need to elaborate a "common Christan response" to the Muslim letter, "otherwise the opportunity may be lost".

He told Vatican Radio Muslim and Christian leaders should meet "face to face" and had to ensure that "good religion" prevailed over "bad religion", which was misused for violent ends. The Pope also said that "in a world wounded by conflicts, where violence is justified in God's name, it's important to repeat that religion can never become a vehicle of hatred...On the contrary, religions can and must offer precious resources to build a peaceful humanity".

Before leaving for Rome the Pope prayed at Naples Cathedral before the bones and blood of San Gennaro (St Januaris), a third-century martyr and the patron saint of Naples. The saint's dried blood, contained in phials, is said to miraculously liquefy twice a year, and Neapolitans believe that if it does not disaster will befall the city.

Following the Pope's address the multi faith assembly opened last night Sunday with a ceremony at the San Carlo Opera House addressed by a monk from Burma and attended by Romano Prodi, the Italian Prime Minister, as well as the Presidents of Tanzania and Malawi, Jakaya Mikwete and Bingu Wa Mutharika, and the Presidents of Ecuador and Kazakhstan, Rafael Correa Delgado and Kassym-Jomart Tokayev.

Last autumn Benedict failed to attend the annual Sant Egidio inter faith conference at Assisi, which John Paul II had supported. Instead he travelled to his native Bavaria, where he enraged many in the Muslim world by appearing to suggest that Islam was inherently violent during a speech at Regensburg University, his alma mater.