Islamic State claims responsibility for Cairo bombing
The militant group said a suicide bomber had detonated his explosive belt inside the church.
Islamic State has claimed responsibility for a suicide bombing at Cairo's main Coptic cathedral that killed 25 people, mainly women and children.
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.
It also threatened more attacks against Christians.
"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.