ISTANBUL, (Reuters) – Dozens of nationalists protested against Pope Benedict’s visit to mainly Muslim Turkey on Thursday, urging him to stay away from a building that was Christianity’s largest church before being turned into a mosque.

Police arrested one man trying to make a speech at a police arricade next to Aya Sofya, now a museum, and after a short stand- off with several hundred riot police at a nearby square the nationalist Grand Unity Party (BBP) protesters peacefully dispersed.

“Next they will try to make Istanbul Constantinople again. We will not allow that,” Bayram Karacan, head of the BBP’s Istanbul wing, told the 100-strong crowd after Muslim prayers.

Later on Thursday Benedict will visit the Aya Sofya, known by its Greek name Hagia Sophia (Church of Holy Wisdom) during the Byzantine period, when Istanbul was called Constantinople.

Protesters waved banners displaying “Pope get out of Turkey” and chanted “Aya Sofya is Turkish and will remain Turkish”.

Police have sealed off Aya Sofya and the famous Blue Mosque, which the Pope will also visit, with security barricades.

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 turned into a museum in 1934.

Nationalist and Islamist Turks were outraged when Pope Paul VI prayed at the museum in 1967, causing a diplomatic incident.

Turkish police have been deployed in force during Benedict’s visit, but protests have been small.