At least 41 people were killed and 45 injured in a fire inside a church in the Egyptian city of Giza on Sunday.
An electrical fire broke out during Mass as 5,000 people gathered at the Coptic Abu Sifin church in the Imbaba neighbourhood, the sources said.
The fire blocked an entrance to the church, causing a stampede, they said, adding that most of those killed were children.
"People were gathering on the third and fourth floor, and we saw smoke coming from the second floor. People rushed to go down the stairs and stared falling on top of each other," said Yasir Munir, a worshipper at the church.
"Then we heard a bang and sparks and fire coming out of the window," he said, saying he and his daughter were on the ground floor and able to escape.
Giza, Egypt's second-largest city, lies just across the Nile from Cairo.
"I offer my sincere condolences to the families of the innocent victims that have passed on to be with their Lord in one of his houses of worship," said Egyptian president Abdel Fattah al-Sisi in a tweet.
Syrian rebels declared President Bashar al-Assad ousted after seizing control of Damascus on Sunday, forcing him to flee and ending his family's decades of rule after more than 13 years of civil war in a seismic moment for the Middle East.
Palestinian health officials said on Sunday that Israeli forces had shelled the Kamal Adwan Hospital in the northern Gaza town of Beit Lahiya, damaging electricity and oxygen pumps and disrupting urgent surgeries.
US President-elect Donald Trump said on Sunday that Russia's abandonment of Syrian President Bashar al-Assad led to his downfall, adding Moscow never should have protected him in the first place and then lost interest because of a war in Ukraine that never should have started.
The Kremlin said on Sunday that Russia was open to talks on Ukraine after US President-elect Donald Trump called for "an immediate ceasefire and negotiations".