The Palestinian Army of Islam denied any involvement in the Two Saints Church attack on New Year’s.
"The Army of Islam has no relation, whether close or distant, to the attack on the Coptic church," in the Mediterranean city of Alexandria, a spokesman for the group, who gave his name as Abu Muthanna, told AFP.
"The Mossad (Israeli intelligence) was responsible for the attack."
Egypt's Interior Minister Habib Al-Adly accused the group on Sunday of having masterminded the New Year's church attack in Alexandria that killed more than 20 people.
The Palestinian group Army of Islam, "which has links to Al-Qaeda, is behind the attack on Al-Qiddissin church in Alexandria," Adly said in a speech to mark Police Day, carried live on state television.
An Egyptian security official told AFP that five Egyptians were arrested around 10 days ago in Alexandria in connection with the attack.
"During questioning, the members of this group said that the planning of the attack had come from abroad," the source said.
Later on Sunday, the interior ministry said an Egyptian had been arrested linked to the Army of Islam who confessed to having been contacted by the group which asked him to help its members sent to carry out the attack.
Ahmad Lotfi Ibrahim Mohammed, a university graduate and native of Alexandria born in 1984, had admitted in writing to his involvement, it said in a statement.
A ministry statement said he had visited Gaza in 2008, where he met members of the extremist group who influenced him to attack Churches in Egypt. The authorities said Mohamed maintained contact with the group until the time of the attack.