The bomber could have been both a Muslim Brotherhood supporter and a supporter of the Islamic State. Although rivals, the two have the same outlook and goals, and the bomber was from one or the other, as I explained here.
“Islamic State claims responsibility for Egypt church bombing that killed 25,” Associated Press, December 13, 2016:
CAIRO — The Islamic State group claimed responsibility Tuesday for a suicide bombing at a Cairo church two days earlier that killed 25 people, highlighting a new escalation of violence in Egypt against civilians and Christians in particular.
In a statement circulated online, it said the bomber had killed and injured 80 people, vowing “to continue war against apostates.” The Egyptian government had earlier released footage showing images said to be that of the alleged suicide attacker.
President Abdel-Fattah el-Sissi on Monday identified the bomber as 22-year-old Mahmoud Shafiq Mohammed Mustafa in the attack, which killed mainly women. IS named the bomber by what appeared to be a nom de guerre, Abu Abdullah al-Masri.
The video was a recording of CCTV footage from outside a chapel adjacent to St. Mark’s Cathedral, seat of Egypt’s ancient Coptic Orthodox Church. It shows a dark figure crossing the street and walking through the gates of the church. Moments later, the blast sends clouds of dust and debris through the windows….
However, the Egyptian government says that the Islamic State’s great rival was involved: “Egypt says church bomber linked to Muslim Brotherhood,”by Lin Noueihed and Ahmed Mohammed Hassan, Reuters, December 13, 2016:
A suicide bomber who killed at least 25 people in Cairo’s main cathedral on Sunday was a Muslim Brotherhood supporter who joined a militant cell while on the run from police, the Interior Ministry said.
In an interview with Reuters, the mother of the alleged bomber said he had been sexually abused in police custody in 2014, but she had seen no sign he had been radicalized.
At least 49 people were wounded when the bomb went off in a chapel adjoining St Mark’s Cathedral, Cairo’s largest church and seat of the Coptic Christian papacy.
The interior ministry named the attacker on Monday as Mahmoud Shafik Mohammed Mostafa, a 22-year-old student. President Abdel Fattah al-Sisi said four people had been detained and two were on the run.
Sisi took power in 2013, deposing Mohamed Mursi of the Muslim Brotherhood, and has since outlawed the Islamist movement as part of a crackdown in which hundreds of its supporters have been killed and thousands jailed.
The Interior Ministry said Mahmoud was arrested in March 2014 for carrying arms during a protest, and was freed on bail after two months. It said he had joined a cell led by Mohab Mostafa Sayyed Qassem, a militant with links to Islamic State fighters in Northern Sinai and exiled Brotherhood officials in Qatar, and was wanted in two other cases.
“MAHMOUD WOULD NOT DO THIS”
Sitting in a two-storey house with her four daughters, his mother, Umm Bilal, said Mahmoud fled to Sudan shortly after being released.
“Mahmoud would not do this… he would not kill anyone,” she shouted as she listened to a news report on the bombing.
Mahmoud’s father died two years ago, said Umm Bilal, who wore a robe and Islamic face covering, or niqab. The young man called his mother regularly from abroad.
“He said he would not return because security forces would detain him again,” Umm Bilal said, adding that the last call came about a week ago.
“He was asking after me and his sisters… I didn’t notice any change in his voice or anything to suggest he would blow himself up.”…