An Al-Qaeda linked group in Gaza was behind the New Year's Eve suicide bombing that killed at least 21 and wounded about a hundred outside a church in the Mediterranean port city of Alexandria, the country's interior minister announced Sunday in his speech marking Police Day.
Interior Minister Habib El-Adly said "conclusive evidence" showed that the shadowy, Gaza-based Palestinian Islamic Army was behind the planning and execution of the attack, which sparked three days of Christian rioting in Cairo and several other cities.
"If elements of the Palestinian Islamic Army, linked to al Qaeda, thought they had hidden behind elements that were recruited, we have decisive proof of their heinous involvement in planning and carrying out such a villainous terrorist act," El-Adly said.
It was the deadliest attack against Christians in Egypt in more than a decade.
The identification of a foreign-based group as the perpetrator of the bombing provides authorities with key support to their contention that sectarianism was not behind violence against Christians and that al-Qaida has no significant foothold in Egypt.
El-Adly's announcement came in an address he delivered during a ceremony marking "Police Day" that was attended by President Hosni Mubarak, cabinet ministers and top police officials.
In a separate address, Mubarak vowed that his government will "triumph over terror" and that he will do his utmost to maintain unity between Egyptians.
"I will not be lenient with sectarian actions from either side and will confront their perpetrators with the might and decisiveness of the law," said Mubarak, Egypt's ancient ruler of nearly 30 years, during which he decisively crushed an Islamist insurgency in the 1990s.
Mubarak, in his own speech marking Police Day, praised the police for finding out who was responsible for the bombing and said the attackers had "tried to sow discord between Copts and Muslims".
Security officials said an unspecified number of people have been detained in connection with the Alexandria bombing but gave no more details. They spoke on condition of anonymity because they were not authorized to share the information with the media.
The Palestinian Islamic Army is thought to have participated in the kidnappings of Israeli soldier Sgt. Gilad Schalit in 2006 and BBC journalist Alan Johnston, who was later released.
Late last year, Israel killed three members of the group in separate airstrikes, alleging the men had planned to attack Israeli and American targets in Egypt's Sinai Peninsula.
The Palestinian Islamic Army considers leaders of al Qaeda as spiritual mentors and endorses its ideology, though it has never admitted direct links to the group.
An Iraq-based al Qaeda group had called for attacks on Egypt's Christians, who make up one tenth of the population, before the church bombing.