Egyptian President Abdel-Fattah El-Sisi announced three days of mourning for the 24 Coptic Christians killed in a bombing of a Cairo chapel near St. Mark's Cathedral.

Sisi informed details about the suicide bomber in a state funeral after the correction of Health Ministry's records on the killed victims. The previous report of 25 victims was changed to 24 after recognizing the 25th body as that of the suicide bomber.

Sisi stated that the bomber is a 22-year-old man named Mahmoud Shafiq Mohammed Mustafa. The president said that that four others, three men and a woman, were arrested in connection with the attack, while two others have not been found.

Sisi did not indicate any groups that could be behind the attack, but strongly hinted the Muslim Brotherhood, which is led by the former president Mohamed Morsi overthrown by the military in 2013. He indicated that it must be the doing of the forces that "have spent three years trying to shake us," a time when Sisi's government was sweeping the Brotherhood supporters and putting them in jail, according to New York Times.  

Sisi's claim is backed up by police Major-General Tarek Attia who stated that Mustafa was previously jailed in 2014 at Fayoum Province in Cairo because of being a member of the Muslim Brotherhood, according to Aljazeera.

Details also point to the possibility of the bomber's involvement with a Salafist group like Al Qaeda. After Mustafa's arrest of 2014, he was said to be tortured and released in 2015, according to his representing lawyer Yasmin Hosam El Din. After that time, Mustafa lived under the alias Abu Dagana el-Kanani, which is a strong indication of conceivable recruitment by Islamic State.

"There have been numerous cases of Egyptian Islamists who went to Libya and the Levant, by way of Sudan, and dived into the fight with Islamic State," Mokhtar Awad, researcher in Program on Extremism at George Washington University, said. He stated that the case of Mustafa showed similarity and consistency with how the Salafist groups work and operate in Egypt.

Other groups said that the President Sisi contributed to this insurgence when his government tortured thousands of opposition arrested which resulted to young Egyptians resorting to extreme measures of radical actions.

Various groups and individuals condemned the attack, like foreign ministers of UAE, France, and the United States.

"As long as we are together as one, we will definitely win, because we are people of goodness, not evil, and people of building, not destruction," Sisi said in the state funeral. Only the victims' families are allowed inside the Virgin Mary and St Athanasius church along with Pope Tawadros II and government and military officials.