Pope Benedict XVI has conducted an open-air mass on the Beirut waterfront and prayed for peace and harmony in the Middle East.

"In a world where violence constantly leaves behind its grim trail of death and destruction, to serve justice and peace is urgently necessary," said Benedict, leading the mass.

"I pray to the Lord specifically to make the Middle East servants of peace and reconciliation so that everyone can live in tranquillity and dignity."

Hundreds of thousands of Christians from across the Middle East braved the scorching heat to take part in the mass.

Benedict is on the final leg of his three-day visit to Lebanon, where one-third of the population is Christian.

The trip was aimed at promoting peace and harmony among religions, and the peaceful co-existence of different faiths.

As part of his visit, the pontiff met Lebanese political leaders including President Michel Sleiman (a Maronite Christian), Prime Minister Najib Mikati (a Sunni Muslim) and the Parliament Speaker Nabih Berri (a Shi'ite Muslim). He also met MPs, cabinet ministers and religious leaders.

The 85-year-old leader of the Catholic Church urged multi-faith Lebanon to become a model for the rest of Middle East.

"In Lebanon, Christianity and Islam have lived in the same space for centuries," said the Pope at the presidential palace.

"It is not unusual to find, in the same family, both religions. If this is possible in one single family, why would it be impossible at the level of the society as a whole?"

On the first day of his visit to Lebanon, Benedict called for a halt to the export of weapons to Syria, and an end to that country's 19 months of violent civil strife.

He called the sale of weapons to Syria a "grave sin".

The Pope's visit to Lebanon coincided with protests across the Islamic world against the US-made anti-Islam film Innocence of Muslims.

Scroll through the pictures to follow the Pope's visit to Lebanon and the open air mass in Beirut: