A historic Ottoman-era mosque in northern Greece which was undergoing renovations was severely damaged in an early-morning fire on Wednesday, according to local media.
The cause of the blaze in the mostly wooden Sultan Bayezid mosque in Didymoteicho town remains unknown.
However, Greek news agency ANA-MPA reported that an electrical fault could be responsible. Culture Ministry official Maria Andreadaki-Vlazaki is expected to visit the site later on Wednesday.
The wooden roof of the mosque, which was a special architectural feature, was completely destroyed, ANA-MPA added.
Construction of the Sultan Bayezid mosque, also known as the Sultan Celebi Mehmet mosque, started in 1389 and was completed in 1420, during the early-Ottoman era.
In 2010 the Greek authorities decided to restore the mosque; work was due to be finished this year.
The building had been closed to worship.