Muslim prayers held in Hagia Sophia in Istanbul on Wenesday night and broadcast by state television channel TRT have been condemned by the Greek Foreign Ministry in a statement issued on Thursday.

“Hagia Sophia is a UNESCO world heritage site. The attempt to convert it into a mosque – through reading of the Koran, holding of prayers, and a number of other actions – is an affront to the international community, which needs to be duly mobilized and to react,” read the ministry’s statement.

The prayers were held to mark Laylat al-Qadr, also known as the Night of Power, which is considered to be the holiest night of the year for Muslims.

The religious program has been held at Hagia Sophia since 2015, and Greek authorities have continued to condemn the act.

In its statement, the ministry went on to say that it was an “unacceptable challenge to the religious sentiments of Christians everywhere and to all those who honor humanity’s cultural heritage”.

They said that it is taking place during a time in the world when the interfaith dialogue should be promoted rather than undermined.

“We call on Turkey to conduct itself as a modern and democratic country, to protect the ecumenical nature of Hagia Sophia, and to respect the age-old tradition of this global monument,” the ministry added.

Hagia Sophia was the biggest church constructed by the East Roman Empire in Istanbul, and has a turbulent history, demolished and reconstructed three times.

After Istanbul was conquered in 1453, it was renovated into a mosque.