Egypt’s Coptic Church, citing health officials, says fire at Cairo church kills at least 41 people.

The blaze ripped through the church in Cairo’s densely populated neighborhood of Imbaba. It was not immediately clear what caused the blaze. An initial investigation blamed an electric short-circuit, police said.

Fifteen firefighting vehicles were dispatched to the scene to put out the flames while ambulances ferried the casualties to nearby hospitals.

The Health Ministry said ambulances have transferred at least 55 injured to hospitals and ministry spokesman Hossam Abdel-Ghafar said at least one person was killed.

President Abdel Fattah el-Sissi spoke by phone with the Coptic Christian Pope Tawadros II to offer his condolences, the president’s office said.

Copts comprise about 10% of Egypt’s primarily Muslim population.