Egypt Breaking: 21 Killed in Car Bomb Attack on Christian Church

LATER UPDATES: "Up to 50" Killed in Bombing of Alexandria Church

UPDATE 1530 GMT: A picture from the post-bombing protests in Alexandria today:

UPDATE 1510 GMT: Protesters and police are clashing near the site of today's bombing. There are reports of injuries and suffocation from tear gas used by anti-riot forces.

A hospital spokesperson said four protestors were seriously injured and will undergo surgery. Seven others had minor injuries.

A few thousand demonstrators gathered in the area of Mar Morcos, near the bombed Al-Qiddissine church and the Mari Girgis hospital, chanting “Muslims and Christians will not be disunited”.

Despite the call of unity, there were reports of clashes between Coptic Christians and Muslims, with about a dozen injuries, just after the bombing.

UPDATE 1500 GMT: Opposition figures have blamed the Government for today's attack. Mohamed ElBaradei, former International Atomic Energy Agency head, said a regime which is “incapable of protecting its citizens should go".

Ghad Party founder Ayman Nour called for the dismissal of Minister of Interior Habib al-Adli, saying he has failed to combat terrorism. Gamal Eid, head of the Arab Network for Human Rights Information, also made the demand.

President Hosni Mubarak had vowed to track down the perpetrators, whom he implied were foreigners as he said they will not “escape punishment from Egyptians”.

UPDATE 1045 GMT: The Interior Ministry says that the attack may have been carried out by a suicide bomber.

A car bomb attack on a Coptic Christian church in the Sidi Bechr district of Alexandria has killed 21 people and injured 79 others.

The automobile exploded as worshippers were emerging from a midnight mass at the Al-Qiddissine (The Saints) church. The Shark Al-Madina Mosque across the street was also damaged. 

Members of the Christian congregation demonstrated into the early hours . Some reportedly made a brief attack on the mosque but were stopped by police.

President Hosni Mubarak's office responded with a call "on children of Egypt -- Copts and Muslims -- to close ranks and confront the forces of terrorism and those who want to undermine the security, stability and unity of the children of this nation".