Pope Benedict XVI has appealed for a halt to the flow of arms into Syria, saying it would help end a civil war that has killed many thousands of people and which Christians fear could bring Islamists to power.
In his strongest comments yet on the conflict, Benedict branded the weapons imports as a "grave sin" as he arrived on Friday at the start of a three-day visit to Beirut, the Lebanese capital just 50km from the Syrian border.
He also described Arab uprisings as a positive "cry for freedom" as long as they included religious tolerance – the central theme of Benedict's trip which is focused on promoting peace in the Middle East and harmony between its minority Christians and majority Muslims.
Christian, Sunni and Shia Muslim and Druze religious leaders joined Lebanon's political elite in greeting Benedict on his arrival in a region now rocked by violent protests against an American film that denigrates Islam.
"The import of weapons has to finally stop," Benedict, 85, told journalists on the plane. "Without the import of arms the war cannot continue. Instead of importing weapons, which is a grave sin, we have to import ideas of peace and creativity."
The Arab Spring uprisings against authoritarian leaders were "a positive thing. There is a desire for more democracy, more freedoms, more cooperation and renewal," he said.
But he added that it had to include tolerance for other religions. Asked about Christian fears about rising aggression from Islamist radicals, Benedict said: "Fundamentalism is always a falsification of religion."
All main faith groups in Lebanon, which was gripped by civil war along sectarian lines from 1975 to 1990, have welcomed his visit.
Among banners greeting Benedict on the road from the airport were several from the Shia group Hezbollah.
The Vatican spokesman, Reverend Federico Lombardi, later said the pope had no specific message for the Syrian leadership but only expressed "general moral principles ... as a moral religious figure and not a politician".
His comments about stopping weapons could draw criticism from Gulf Arab countries that - with Western blessing - support arming the rebels trying to topple President Bashar al-Assad.
Syrian rebels took up arms after mainly peaceful protests were met with brutality by Assad's regular forces and armed groups.
For his part, Assad - whose main arms supplier has been Russia - says he faces a "terrorist" campaign to overthrow him and has pledged to stamp it out. Neither side has shown any inclination to negotiate.
Protests in north
Clashes from the Syrian war - an opposition group says more than 27,000 people have been killed in the uprising - have occasionally spilled over into Lebanon, evoking fears of renewed strife there.
Tensions have been rising between Lebanon's Sunni Muslims, who generally back the uprising led by Syria's Sunni majority and Shia who usually support Assad's minority Alawite sect, an offshoot of Shia Islam.
In the mainly Sunni Muslim northern city of Tripoli one person was killed in clashes with security forces after protesters set fire to a US fast food restaurant and tried to storm a government building.
At least 14 people were wounded, most of them from the security forces.
Witnesses said the crowd chanted against the pope's visit and shouted anti-American slogans in protests over a film insulting the Prophet Muhammad. "We don't want the pope," and "No more insults (to Islam)," they chanted.
Benedict angered Muslims early in his papacy by suggesting in a 2006 lecture that Islam was violent and irrational. He said this was a misunderstanding and visits to Turkey later that year and Jordan in 2009 largely calmed the controversy.
More than 5,000 military and security personnel were being deployed to protect the pontiff, al-Nahar newspaper said. Beirut airport closed for two hours on his arrival and roads on his route through the capital were closed.