Re-posted from the BBC.
A small Palestinian group linked to al-Qaeda was behind the New Year's Day bomb attack on a church in Alexandria in which 23 people died, Egypt says.
Interior Minister Habib al-Adli said Cairo had "decisive proof" that the Army of Islam carried out the attack in the northern Egyptian city.
The Gaza-based group immediately denied any responsibility for the attack.
Officials in Egypt have so far released very few details how they believe the attack was carried out.Shadowy group
"We have decisive proof of their (Army of Islam's) heinous involvement in planning and carrying out such a villainous terrorist act," Mr Adli said in a speech to mark Police Day in Egypt.
President Hosni Mubarak praised police, saying the development would help "set at rest the hearts of all Egyptians".
The Alexandria attack triggered days of rioting by Egypt's minority Christians, who accused the government of not doing enough to protect them.
A spokesman for the Army of Islam said on Sunday that the group "has no connection to the church attack in Egypt".
|The attack triggered days of clashes between Coptic Christians|
But he added: "We praise those who did it."
The Army of Islam has been blamed for kidnappings and other violence inside Gaza.
It is alleged that the group played a part in the kidnapping of Israeli soldier Gilad Shalit in 2006.
But there is no record of it operating further afield, the BBC's Jon Leyne in Cairo reports.
Our correspondent adds that the Egyptian government early on stressed their belief that there was foreign involvement - rather than it just being a sectarian religious attack carried out by Egyptians.