Pope Benedict XVI has called on Middle Eastern Christians to work towards peace and reconciliation, stressing again the central theme of his visit to Lebanon, whose neighbour Syria is engulfed in a civil war.
He has also urged Christians not to leave the region, despite war and growing pressure from radical Islamists.
"May God grant to your country, to Syria and the Middle East the gift of peaceful hearts, the silencing of weapons and the cessation of all violence," Benedict, 85, said on Sunday at the end of Mass on the final day of his trip to Lebanon.
Lebanon, torn apart by a 1975-1990 sectarian civil war, is a religious mosaic of more than four million people whose Muslim majority includes Sunnis, Shi'ites, Alawites and Druze.
About a third of the population is Christian, divided into more than a dozen churches.
Benedict's open-air Mass on Beirut's Mediterranean seafront was attended by 350,000 worshippers,
according to the organisers' estimate.
"In a world where violence constantly leaves behind its grim trail of death and destruction, to serve justice and peace is urgently necessary," Benedict said at the Mass, praying for "Middle East servants of peace and reconciliation".
"This is an essential testimony which Christians must render here, in co-operation with all people of good will."
Benedict conducted the Mass in French and Latin and lay people also offered prayers in Arabic, Armenian, Greek and English.
Al Jazeera's Rula Amin, reporting from Beirut, said that this was one of the key themes of Benedict's visit.
"The Vatican and the Christian community are very concerned that all this violence in the region will actually push some Christians to leave this country," she said.
Benedict appealed on Friday for an end to the import of weapons into Syria, branding it a "grave sin" and saying a halt to the arms flow could help end the civil war.
Activists say more than 27,000 people have been killed in Syria's 18-month-old mainly Sunni Muslim uprising against
President Bashar al-Assad, who belongs to the minority Alawite sect that grew out of Shi'ite Islam.
Few of Syria's Christians, about 10 per cent of Syria's population, have joined the uprising against Assad, fearing that it could bring hostile Islamists to power in Damascus.
All faiths in attendance
Politicians from all sectors of multi-faith Lebanon attended Sunday's Mass, held on reclaimed land next to the port.
Leaders of the country's main religious had all assured the Vatican of their support for the visit in advance.
With no shade from the hot sun for the crowd, many fanned themselves as temperature rose over 30 degrees centigrade.
Benedict was seen mopping sweat from his forehead at one point although the altar was under a canopy.
Red Cross workers carried away at least two worshippers who fainted from the heat halfway through the celebration.
Many in the crowd wore white caps bearing the motto of the visit, "salami o-tikum!" (Arabic for "my peace I give to you"), a phrase Benedict has repeated in several speeches.
Cedars of Lebanon, the country's symbol, featured on a white backdrop to the altar where Benedict presided over Mass, and on white capes worn by prelates of the Maronite Church, the largest of six Lebanese Christian churches linked to the Vatican.
Closed to traffic
Prelates from other Eastern Catholic churches stood out in their distinctive gold or black vestments, in contrast to the green chasuble worn by the pope. Hymns in Arabic added a local touch to the Gregorian and classic Catholic works being sung.
Streets near Beirut port were closed to traffic in the morning and soldiers manned main intersections. Three military helicopters buzzed overhead and a navy ship patrolled offshore.
There were some pre-visit concerns about security because of a wave of protests across the Muslim world against an anti-Islam film produced in the US. One protester was killed on Friday in violence in the northern Lebanese city of Tripoli.
Several in the crowd were heartened by Benedict's repeated calls for Christians to stay in the Middle East, where war, emigration and discrimination have cut their ranks to five per cent of the population now compared to 20 per cent a century ago.
A Filipino maid named Julianne, 31, said: "Everyone thinks the Middle East is only about Muslims, but there is a big
Christian community and we should celebrate too."
"His message is to give us pride and encouragement that it is worth the effort to work for coexistence and understanding and to ensure Christians remain here," said Lebanese Maronite Silva Mansour, here with her husband and one-month-old baby.