Security is tight in Istanbul in preparation for what is expected to be the day on which the visit of Pope Benedict XVI to Turkey could provoke most anger among local Muslims.
Entire areas of the city, those closest to the papal itinerary, have been sealed off to traffic, with large numbers of armed police on duty and police snipers on roofs.According to some estimates, there are 15,000 police on duty in Istanbul, compared to 3,000 in Ankara on Monday.
Details of the pope's itinerary in the city, as well as the venues he is to attend, were not being confirmed last night. The main focus today will be his visits to the Hagia Sophia museum and to the Blue Mosque, probably in the afternoon. Both are close to one another in the Sultanahamet area of Istanbul.
The Hagia Sophia museum was a church which was regarded as the greatest in Christendom until 1453 when it was taken over by Muslims and turned into a mosque. It remained a mosque until 1935 when it became a museum. Fundamentalist Muslims opposing the papal visit have been saying that Pope Benedict plans to say Mass in Hagia Sophia today as he tries to claim it back for Christianity. The pope has no such plans, but the claims are believed in Istanbul.
His visit to the Blue Mosque will be his first as pope to a mosque. How he handles that visit could have as dramatic an effect on Muslim attitudes as Pope John Paul's praying in the manner of a Jew at the Western Wall in Jerusalem in 2000. It saw an indifferent Israeli population suddenly transformed into enthusiasts.
Later this evening the pope will meet representatives of the various religions in Istanbul as well as representatives of Catholic communities throughout Turkey.
His open-air Mass yesterday at the Meryem Ana Evi in Ephesus, which is traditionally believed to have been the home of Mary in her latter years, was attended by a small congregation of local Christians under very tight security. In his homily the pope described the Christian community in Turkey as "a small minority which faces many challenges and difficulties daily".
Local Muslim people turned out to welcome him, the first time this has happened on the visit.
Last night the pope was met by Ecumenical Patriarch Bartholomew, nominal head of 300 million Orthodox Christians. The patriarch welcomed him with "sentiments of sincere joy".