Pope Benedict XVI visited the Blue Mosque in Istanbul Thursday, becoming the second pope to enter a Muslim place of worship. He also visited Aya Sophia, which used to be Christianity's largest church. Earlier the pope held a solemn prayer service with the leader of the world's Orthodox Christians. Sabina Castelfranco reports from Istanbul.
 
Pope Benedict removed his shoes before entering the 17th century BlueMosquein Istanbul. It was the second time a pope has entered a Muslim place of worship. Pope John Paul II visited a mosque in Syria in 2001.

Istanbul's Grand Mufti Mustafa Cagrici accompanied the pope and described different details of the mosque. The pope stood silently in meditation. His visit to the mosque was seen as another gesture of reconciliation by the pope toward Muslims.

Vatican spokesman Federico Lombardi said the visit to the mosque in Istanbul was added to the pope's schedule as a sign of respect to Muslims. The pope and the grand mufti exchanged gifts inside the mosque.

Earlier the pope visited the domed Aya Sofia, or Church of Holy Wisdom. During the Byzantine period, it used to be Christianity's largest church. In 1453 it was turned into a mosque and now it is a museum.

Extra tight security was in place for the pope's evening visits in Istanbul.

In the morning Thursday, Pope Benedict and the spiritual leader of the world's Orthodox Christians, Ecumenical Patriarch Bartholomew, held a solemn prayer service together in the Church of Saint George in Istanbul.

During the ceremony the leaders of the world's Catholics and Orthodox pledged to continue all efforts toward full Christian unity between their churches.

"'The divisions which exist among Christians are a scandal to the world and an obstacle to the proclamation of the Gospel," said Pope Benedict XVI.

In a joint statement after the ceremony, the pope and thepatriarchalso stressed the need to "preserve Christian roots" in European culture while remaining "open to other religions and their cultural contributions."