Egypt’s Coptic Church has said 41 people were killed and 55 were injured in a fire at a church in the city of Giza, near Cairo

At least 40 people were killed and 45 injured in a fire inside a church in the Egyptian city of Giza on Sunday, two security sources told Reuters.

An electrical fire broke out during Mass as 5,000 people gathered at the Coptic Abu Sifin church in the Imbaba neighborhood, 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 started 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.