The Pope has arrived in Lebanon to urge peace at a time of great turmoil in the Middle East.

The three-day visit comes at a time of turmoil in the region - the civil war in neighbouring Syria and in the aftermath of a mob attack that killed several Americans in Libya, including the US ambassador.

Pope Benedict XVI was welcomed by leaders including the Lebanese president, prime minister and parliament speaker as well as Christian and Muslim religious leaders. Cannons fired a 21-shots salute.

The Pope told reporters on the plane that imports of weapons to Syria is a "grave sin". Syria's rebels have appealed for weapons shipments to help them fight the regime.

The visit brings the Pope to the nation with the largest percentage of Christians in the Middle East - nearly 40% of Lebanon's four million people, with Maronite Catholics the largest sect. Lebanon is the only Arab country with a Christian head of state.

Lebanese authorities are enacting stringent security measures, suspending weapons permits except for politicians' bodyguards and confining the visit to central Lebanon and the northern Christian areas.

Army and police patrols were stationed along the airport road, which was decorated with Lebanese and Vatican flags as well as posters of the Pope and "welcome" signs in different languages.

Pope Benedict told reporters on the plane he was not afraid to visit Lebanon. He also described the Arab Spring that has already removed four long-serving dictators as "positive".

"It is the desire for more democracy, for more freedom, for more co-operation and for a renewed Arab identity," the Pope said. He warned against the risk that the push for more freedom could end intolerance for other religions.

The Pope said he never considered cancelling the trip for security reasons, adding that "no one ever advised (me) to renounce this trip and personally, I have never considered this".

He denounced religious fundamentalism, calling it "a falsification of religion".

Pope Benedict, the third pope to visit Lebanon after Paul VI in 1964 and John Paul II in 1997, will be addressing concerns from the region's bishops over the plight of Christians in the Middle East. War, political instability and economic hardships have driven thousands from their traditional communities, dating to early Christianity in the Holy Land, Iraq and elsewhere.

"Let me assure you that I pray especially for the many people who suffer in this region," he said upon arrival.

The Vatican initially stressed Pope Benedict's push for inter-faith dialogue in the wake of US ambassador Chris Stevens' death in a mob attack on the consulate in Benghazi, Libya, earlier this week. But yesterday the Holy See toughened its response, firmly condemning the attack and saying nothing can justify such acts of terrorism or violence.

The papal visit comes amid fears that Syria's conflict might spill over to Lebanon. Clashes in Lebanon between Syrian groups over the past months have claimed the lives of more than two dozen people and left scores wounded.

The Christian community in Lebanon is divided between supporters and opponents of Syrian president Bashar Assad.

Among Assad's supporters is former Lebanese prime minister and army commander Michel Aoun, a strong ally of the militant Hezbollah group. Hezbollah's leader Sheik Hassan Nasrallah welcomed the pontiff's visit, describing it as "extraordinary and historic".

The Pope said: "I have come to Lebanon as a pilgrim of peace. As a friend of God and as a friend of men."

President Michel Suleiman said in a welcoming speech: "We are hopeful that your visit to our country will bring good to the Lebanese and the people of this region, including eastern Christians who are rooted in this land. We welcome you on a sacred land."

MAN KILLED IN PROTEST

One demonstrator was killed and two others were wounded in clashes with security forces in the northern Lebanese city of Tripoli in protests over a film insulting the Muslim Prophet Mohammad and against the pope's visit to Lebanon.

A security source said the man was killed as protesters tried to storm a government building. Earlier, a US fast food restaurant was set alight. Twelve members of the security forces were wounded by stones thrown by protesters, the source said.

The US-made film has sparked violent protests in Libya, where the US ambassador and three other Americans were killed, and in Egypt, Yemen and Sudan and there are fears the demonstrations could spread to other Muslim countries.

The protests coincided with Pope Benedict's arrival in Lebanon for a three-day visit.

Lebanese security forces had earlier opened fire after protesters torched a fast food restaurant in Tripoli and threw rocks at a state building, shouting anti-American slogans and chanting against the pope's visit to Lebanon.

A Reuters journalist at the scene saw hundreds of protesters dodging gunfire and teargas as they hurled stones at security forces in armoured vehicles. Protesters chanted "We don't want the pope," and "No more insults (to Islam)".