(AFP) - Pope Benedict XVI walks a diplomatic tightrope in Istanbul on Thursday, the third day of his trip to Turkey, with visits to sensitive Muslim and Christian landmarks amid tight security.
The pontiff was to visit Hagia Sophia Museum, the sixth-century basilica that was converted into a mosque in 1453 during the conquest of Constantinople, renamed Istanbul by the Ottomans, reports Trend.
The site is in a modern-day tug-of-war, with Islamists demanding that it be restored as a mosque while fearing that Christians want to point to the pope's visit as proof that it should be reborn as a church.
It was made a museum under the secular Turkish republic proclaimed in 1935.
Benedict, pursuing a key goal of his papacy -- that of healing a rift between the two feuding branches of Christianity that dates back nearly a millennium -- posed for photographs with Bartholomew I, who represents around 150 million Orthodox faithful, on Wednesday evening.
The pair then held private talks at the patriarchal church of St. George, where the pope had earlier celebrated mass.
Tight security was in place in this city of more than 12 million, some 15,000 of whom demonstrated Sunday.
More demonstrations were expected on Thursday when the pope visits the Blue Mosque, just a stone's throw away from Hagia Sophia, becoming the second pope after his predecessor John Paul II to visit a Muslim place of worship.
The pontiff's goal of rapprochement with the Orthodox Church has been upstaged during his four-day trip to Turkey by the need to address simmering anger in the Muslim world over his remarks in September seen as linking Islam and violence.
On Wednesday, the Vatican shrugged off an assertion by a self-styled Islamic emirate in Iraq led by Al-Qaeda that the pontiff's visit to Turkey is part of a "Crusade against Islam."
"Neither the pope nor his entourage have any concern over this type of message, which underscores once again the urgency and importance of a shared commitment by all forces opposed to the use of violence," said Vatican spokesman Federico Lombardi.
Earlier Wednesday, the pontiff was in the historic city of Ephesus where he visited the House of the Virgin Mary and celebrated his first mass on Muslim soil at the location where the mother of Christ is believed to have spent her last years.
"From this edge of the Anatolian peninsula, a natural bridge between continents, let us implore peace and reconciliation, above all for those dwelling in the Land called 'Holy' and considered as such by Christians, Jews and Muslims alike," the pope said in his homily.
The pope's potentially explosive trip got off to an unexpectedly smooth start in Ankara on Tuesday, when both sides traded gestures and words of good will to defuse tensions caused by his remarks in September equating Islam and violence.
Jitters over the pope's visit, his first as pontiff to a Muslim country, led to a security blanket even tighter than that laid out for US President George W. Bush when he visited during a 2004 NATO summit.
The schism between the Eastern and Western Rites was sealed in 1054 after long-running disputes over papal primacy and theological differences.
In 1204, the Fourth Crusade carried out the brutal sack of Constantinople, modern-day Istanbul, further deepening hostilities.
Benedict is following the lead of his late friend and mentor John Paul II, who visited Istanbul in 1979, just one year after he was elected pope, to announce the creation of a joint Orthodox-Catholic committee to resolve differences.
At a meeting at the Vatican in July 2004, John Paul II and Bartholomew I issued a joint declaration for the resumption of Orthodox-Catholic theological talks, suspended in 2000 after a row over the status of Eastern Catholic Churches.
Benedict and Bartholomew I were to meet again early Thursday when they were to issue a joint declaration.