Pope Benedict and the spiritual leader of Orthodox Christians, Patriarch Bartholemew said on Thursday (November 30) minority rights must be protected as the EU expands and appeared to jointly support Turkish membership if it protected religious liberties. In a common declaration after a prayer service in Istanbul, Benedict and Patriarch Bartholomew rejected the concept of killing in God's name, denounced terrorism and re-committed their Churches to the quest for unity and condemned violence in the Holy Land. There are only 120,000 Christians, about 30,000 of them Catholic, in Turkey today, compared to 2 million a century ago. Patriarch Bartholomew, spiritual leader of the world's 250 million Orthodox Christians, strongly supports Turkey's membership in the EU and two days ago the Pope did an about-face from his previous opposition to Ankara's bid. Pope Benedict visited Istanbul's Blue Mosque on Thursday (November 30) during his trip to predominantly Muslim Turkey, becoming only the second Roman Catholic Pontiff to ever enter a mosque. The visit was seen as another gesture of reconciliation by the Pontiff after he infuriated much of the Muslim world with comments taken as indicating he believed Islam was violent and irrational. He denied that was his view of the religion. His predecessor Pope John Paul II made the first papal visit to a mosque during a trip to Damascus in 2001. Before visiting the mosque, the Pope visited the nearby Aya Sofya, once Christianity's largest church known by its Greek name Hagia Sophia (Church of Holy Wisdom). On conquering the city in 1453, Sultan Mehmet went to the church and prayed, turning it into a mosque. As part of Mustafa Kemal Ataturk's drive to modernise Turkey, it was secularised and turned into a museum in 1934. Nationalist and Islamist Turks were watching to see if Benedict committed the unlikely faux pas of praying in the museum. Pope Paul VI did so in 1967, causing a diplomatic incident, but Pope John Paul II did not when he was there in 1979. After a short tour of the museum, Benedict crossed Sultan Ahmet Square in the old centre of Istanbul to the mosque. Istanbul's Grand Mufti Mustafa Cagrici escorted Benedict into the Blue Mosque, officially named after Sultan Ahmet and opened in 1616. The Mufti prayed out loud and the Pope appeared separately to pray with his lips moving. The Blue Mosque is the most famoused mosque in Turkey and a popular tourist attraction. It got its popular name from the fine blue Iznik tiles in the main prayer room. Benedict's visit was a late addition to his schedule meant as a gesture of respect for Islam. As the pontiff and grand mufti exchanged pictures of doves, the symbol of peace, Cagrici said, "The visit of the Pope to the Blue Mosque after visiting gorgeous Aya Sofya, which is our common cultural value, will give a new impetus to the inter-religious relations between our believers." Police had sealed off Aya Sofya and the famous Blue Mosque with security barricades. The German-born Pope has already defused much of the tension linked to his visit, his first to a mostly Muslim country, by supporting Ankara's bid to join the European Union and praising Islam as a religion of peace. A few dozen supporters of a nationalist Islamist party protested against the Pope outside Istanbul University under heavy police guard.