JERUSALEM (AFP) - Pope Francis celebrated mass at a contested Jerusalem site on Monday at the end of a whirlwind pilgrimage which he marked by making a personal bid for Middle East peace.

The 77-year-old pontiff, who has made interfaith dialogue a cornerstone of his papacy, made an impassioned call for an end to religious intolerance, saying believers must have free access to sites they consider sacred within the Holy City.

Despite stating that the trip would be "purely religious" he waded into sensitive regional politics, issuing a unique invitation to the Israeli and Palestinian presidents to pray with him at the Vatican to end their "increasingly unacceptable" conflict.

A visibly tired Francis celebrated the last public mass of his visit at the Upper Room on Mount Zion, in which Jesus is believed to have held the Last Supper, where Christians have access but very limited freedom of worship.

Vatican efforts to negotiate greater rights at the Upper Room have sparked opposition from nationalist and Orthodox Jews, who revere part of the building as the tomb of King David, prompting a series of angry protests and several anti-Christian attacks.

Police were called to the Church of the Dormition, about 30m from the Upper Room in the Mount Zion compound, to probe an arson attack carried out shortly after the pope celebrated his mass.

"Someone entered the church and went down to the crypt, took a book that is used by pilgrims to a small room next to the organ, and set some wood crosses on fire," the Benedictine Abbot of the church, Nikodemus Schnabel, told AFP.

Some of the German Benedictine monks from the church were coated in black soot after putting out the fire and there was a strong smell of smoke, said an AFP photographer. A small pile of fire-damaged crosses lay in a smouldering heap and furniture had been damaged.

The Israeli police said it was investigating the fire. "According to initial testimony, a man, not a Jew, entered the Church of the Dormition, grabbed a candle and set fire to a book," said spokesman Micky Rosenfeld.

The pope was seen off in a brief airport ceremony in Tel Aviv by President Shimon Peres and Prime Minister Benjamin Netanyahu.
Earlier, he drove home a strong message about religious intolerance.

He called for "free access to holy sites" in Jerusalem and for a "firm rejection" of intolerance towards "places of worship", in an apparent allusion to extremist hate crimes targeting mosques and churches.

Touring the holiest sites in Jerusalem's walled Old City early Monday, he issued a call for the three religions to "work together for justice and peace" as he was shown around the Al-Aqsa compound, the third holiest site in Islam which Jews also consider sacred.

Entering the exquisite blue-tiled Dome of the Rock with its landmark golden cupola, used as a place of worship for women only, the pope first removed his shoes before walking to visit the smaller, silver-domed Al-Aqsa mosque.

At the Western Wall, the holiest site at which Jews can pray, he left a note in between the ancient stones before sharing an emotional embrace with two close friends travelling with him, Rabbi Abraham Skorka and Islamic studies professor Omar Abboud.

Watching from a distance were a handful of ultra-Orthodox youngsters who shouted : "Tragedy, horrible!" in Yiddish.

Francis had promised the three-day pilgrimage, which began on Saturday in Jordan, would steer clear of political issues.

But at the end of an open-air mass in Bethlehem, where he began the Israel-Palestinian leg of his trip, he invited Palestinian president Mahmud Abbas and his Israeli counterpart Shimon Peres to join him at the Vatican for a "heartfelt prayer" for peace.

Peres told the pope he was happy to accept, while a senior Palestinian official said Abbas would visit the Vatican for the prayer on June 6.

In a further divergence from prepared texts, the pope spoke out against anti-Semitism and religious intolerance and made unscheduled stops which were seized upon as political capital by Israel and the Palestinians.

In Bethlehem he surprised his entourage by hopping out of his white open jeep to touch and briefly pray at Israel's towering concrete separation barrier which cuts through the West Bank city in what the Palestinians hailed as an "eloquent and clear message".

Israel says the barrier, which it began building in 2002, is crucial for security. Palestinians see it as a land grab aimed at stealing territory they want for a future state.

On Monday, he made a surprise stop at an Israeli memorial for victims of militant attacks, reportedly at Mr Netanyahu's request.

Mr Netanyahu thanked the pope for visiting the memorial, telling him it was directly connected to the barrier.

"If the incitement against the state of Israel stops, if terror stops, there won't be a need for the measures that we've taken, like the security fence which has saved thousands of lives," he said.

"After it was set up, the terror stopped." In Jordan, Francis appealed for an end to the bloodshed in Syria, before flying to Bethlehem, in what was seen as a nod towards Palestinian statehood aspirations.

The Vatican denied the pope was pursuing any political agenda, with spokesman Federico Lombardi saying the unscheduled stops were "gestures.. (which) rounded out his official programme." Israel said his visit to the attack victims memorial had balanced out the picture.

"Those who think that he lent towards the Palestinian perspective are wrong," foreign ministry spokesman Yigal Palmor told AFP.
"In going to the attack victims' memorial at Mt Herzl, the pope was able to understand why this barrier was erected."

On Monday, the pope also visited the Yad Vashem Holocaust memorial, where he denounced the "unfathomable abyss" of the Nazi genocide which claimed the lives of six million Jews.