A fire ripped through a church in a densely populated neighbourhood of the Egyptian capital of Cairo on Sunday as congregants worshipped, killing at least 41 and injuring 14, the Coptic Church said.
It was one of the worst fire tragedies in Egypt in recent years.
The cause of the blaze, which produced huge amounts of smoke in the Abu Sefein church in the working-class neighbourhood of Imbaba, was not immediately known. An initial investigation pointed to an electrical short-circuit, according to a police statement.
The Coptic Church cited health officials in reporting the casualty toll. It said the fire broke out while a service was underway.
Fifteen firefighting vehicles were dispatched to the scene to put out the flames while ambulances ferried casualties to nearby hospitals.
President Abdel Fattah el-Sissi spoke by phone with the Coptic Christian Pope Tawadros II to offer his condolences, the president's office said.
"I am closely following the developments of the tragic accident," el-Sissi wrote on Facebook. "I directed all concerned state agencies and institutions to take all necessary measures, and immediately deal with this accident and its effects."
The Health Ministry said ambulances transferred at least 55 injured people to local hospitals. It did not give a death toll.
The Interior Ministry said it received a report on the fire at 9 a.m. local time, and that they found that the blaze broke out in an air conditioner in the building's second story.
The ministry, which oversees police and firefighters, blamed an electrical short-circuit for the fire, which produced huge amounts of smoke.
The country's chief prosecutor, Hamada el-Sawy, ordered an investigation and a team of prosecutors was dispatched to the church.
Egypt's Christians account for some 10% of the nation's 90 million people and have long complained of discrimination by the nation's Muslim majority.
Sunday's blaze was one of the worst fire tragedies in recent years in a country where safety standards and fire regulations are poorly enforced. In March last year, a fire at a garment factory near Cairo killed at least 20 people and injured 24 more.