ISTANBUL: Turkey on Monday reopened a mosque converted from an ancient Orthodox church in Istanbul for Muslim worship, four years after the president ordered its transformation.

The Kariye Mosque was formerly a Byzantine church, then a mosque and then a museum.

President Recep Tayyip Erdogan ordered the building to be reconverted into a Muslim place of worship in 2020.

His order came followed a similarly controversial ruling on the UNESCO-protected Hagia Sophia — a cathedral in Istanbul that was converted into a mosque and then a museum, before becoming a mosque again.

The changes were seen as part of Erdogan’s efforts to galvanise his more conservative and nationalist supporters.

But they have also added to tensions with prelates in both the Orthodox and Catholic churches.

Erdogan on Monday declared Kariye Mosque reopened for worship remotely during a ceremony at the presidential palace in the capital, Ankara.

An AFP picture from the mosque showed one worshipper wave a Turkish flag before the congregation who performed their prayers on a brick-red colour carpet on Monday afternoon.

Images also revealed that two mosaics carved into the walls of the ancient church on the right and left sides of the prayer room were covered with curtains.

Most of the mosaics and frescos however remained visible to visitors.

“I had the opportunity to visit the place before and I was initially a little afraid of the work that could have been carried out,” said Michel, a French tourist, who would not give his full name.

“But ultimately we must recognise that it’s well done, that the frescos are accessible to everybody,” the 31-year-old researcher said.

The decision in 2020 to convert the building drew an angry response from neighbouring Greece, which called the move “yet another provocation against religious persons everywhere”.