The Coptic Orthodox Archbishop of London has spoken of his "great sadness" after a fire in a church in Egypt left dozens dead, including many children.

At least 41 people were killed in the fire that swept through the Coptic Orthodox Church of Abu Sefein in Imbaba, on the outskirts of Cairo, on Sunday.

The death toll includes 18 children and priest, Father Abdel-Messih Bekhit. Dozens more were injured.

Archbishop Angaelos called it a "tragic loss of life".

"What is even more tragic, is that due to the nature of liturgical attendance, many of these fatalities and injuries were multi-generational, with families mourning numerous members," he said. 

"As many bury their loved ones today, and others support survivors in hospitals and at home, we pray repose for those who have sadly departed, comfort for those who mourn them, healing for those who will bear the physical and emotional scars, and support for the families and communities that will continue to recover from this tragedy over the coming weeks, months and even years."

The Archbishop called for a "robust and transparent investigation" into the tragedy after some eyewitnesses claimed that emergency services were slow to respond.

He continued, "Two bittersweet realities arise from this tragedy. The first is that churches in Egypt are filled by the faithful on a regular basis, and so when tragedy strikes it strikes at a high cost, and at the heart of the community.

"The second is that tragedy creates a platform for us to recognise and value one another while experiencing each other's pain and comforting one another through our suffering.

"These tragic moments inevitably lead people from all walks of life to empathise with the suffering of mothers and fathers who weep for their children, children who have lost parents, families who have been torn apart, and friends separated.

"It is in that shared experience that we find hope in our common humanity, and ability to understand, grieve with, respect and value one another and the sanctity of life that we all share.

"Assured of the promise and power of the Resurrection, we bid farewell to those who have departed from this world, and pledge to pray for and support those who remain with us, so deeply affected by this harrowing experience."