CAIRO: Daesh (ISIS) claimed responsibility Tuesday for a suicide bombing at Cairo’s main Coptic cathedral and threatened more attacks against Christians.

The militant group said in a statement that a suicide bomber whom it identified as Abu Abdallah al-Masri had detonated his explosive belt inside the church.

“Every infidel and apostate in Egypt and everywhere should know that our war ... continues,” the group said in the statement, published by its Amaq news agency.

The name it gave for the suicide bomber differed from that announced by Egyptian authorities Monday – Mahmoud Shafik Mohammad Mostafa, a 22-year-old student. It gave no explanation.

Earlier Tuesday, the Egyptian Interior Ministry said the suicide bomber was a Muslim Brotherhood supporter who joined a militant cell while on the run from the police.

In an interview with Reuters, the alleged bomber’s mother said she had seen no sign he had been radicalized.

At least 25 people were killed and 49 wounded in the bombing of the chapel, Cairo’s largest church and seat of the Coptic Christian papacy.

President Abdel-Fattah al-Sisi said four people had been detained and two were on the run.

Sisi took power in 2013, deposing Mohammad Morsi 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 Daesh fighters in Northern Sinai and exiled Brotherhood officials in Qatar, and was wanted in two other cases.

Sitting in a two-story 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 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 a week ago.

Umm Bilal said her son was not radicalized, but had returned broken from police custody. Mahmoud had confided in his brother, she said, that he was sexually assaulted.

Egypt’s oldest Islamist organization says it is peaceful, but has split into rival wings since the crackdown, while some former supporters have formed splinter groups that carry out targeted attacks on police and judicial officials.

CCTV footage surfaced overnight showing a man walking briskly out of the church and another walking in seconds before the blast. Reuters could not verify the authenticity of the footage.