The blast at Egypt's main Coptic Christian cathedral killed dozens of people and wounded many others on Sunday, according to Egyptian state television, making it one of the deadliest attacks carried out against the religious minority in recent memory. (AP)

People stand near St. Mark's Coptic Orthodox Cathedral after an explosion inside the cathedral in Cairo, Egypt December 11, 2016. (Reuters)

Egyptian security forces inspect the scene of a bomb explosion inside the Saint Peter and Saint Paul Coptic Orthodox Church on December 11, 2016, in Cairo's Abbasiya neighbourhood. (AFP)

Egyptian security forces inspect the scene of a bomb explosion at the Saint Peter and Saint Paul Coptic Orthodox Church on December 11, 2016, in Cairo's Abbasiya neighbourhood. (AFP)

A Christian employee at Cairo’s Coptic Cathedral checks for damage from the blast after an explosion inside the cathedral in Cairo, Egypt December 11, 2016. (Reuters)

Egyptian security forces examine the scene inside St. Mark Cathedral in central Cairo, following a bombing, Sunday, Dec. 11, 2016. The blast at Egypt's main Coptic Christian cathedral killed dozens of people and wounded many others on Sunday, according to Egyptian state television, making it one of the deadliest attacks carried out against the religious minority in recent memory. (AP)

Members of the special police forces stand guard to secure the area around St. Mark's Coptic Orthodox Cathedral after an explosion inside the cathedral in Cairo, Egypt December 11, 2016. (Reuters)

Security forces examine the scene inside St. Mark Cathedral in central Cairo, following a bombing, Sunday, Dec. 11, 2016. The blast at Egypt's main Coptic Christian cathedral killed dozens of people and wounded many others on Sunday, according to Egyptian state television, making it one of the deadliest attacks carried out against the religious minority in recent memory. (AP)

A damaged bench inside the St. Mark Cathedral in central Cairo, following a bombing, Sunday, Dec. 11, 2016. The blast at Egypt's main Coptic Christian cathedral killed dozens of people and wounded many others on Sunday, according to Egyptian state television, making it one of the deadliest attacks carried out against the religious minority in recent memory. (AP)

A damaged clock and Egyptian Coptic pope at the scene inside the St. Mark Cathedral in central Cairo, following a bombing, Sunday, Dec. 11, 2016. The blast at Egypt's main Coptic Christian cathedral killed dozens of people and wounded many others on Sunday, according to Egyptian state television, making it one of the deadliest attacks carried out against the religious minority in recent memory. (AP)

An Egyptian man sits at the scene of a bomb explosion that targeted the Saint Peter and Saint Paul Coptic Orthodox Church on December 11, 2016, in Cairo's Abbasiya neighbourhood. (AFP)