Christian protesters clashed with police

The Egyptian President Hosni Mubarak has unged Christians and Muslims in Egypt to unite against "terrorism" after the Saturday's bomb that killed 21 people at a church, this did not stop the angered Christian protesters who took to the streets and clashed with police.

The Ministry of the Interior said evidence showed that the attack on a church in the Mediterranean port city of Alexandria was carried out by a suicide bomber and that it was the work of "foreign elements."

There was no immediate claim, but al-Qaeda has threatened Christians everywhere and called for punishment of Egypt's Copts, over claims that two priests' wives they say had converted to Islam were being held by the church against their will.

Health Minister Hatem el-Gabaly said that at least 12 of the dead have been identified as Christians. Other bodies had yet to be identified. He said initial assessments indicated 70 people were wounded.

State media earlier reported 21 killed in the blast, which struck as worshippers marking the New Year left the church. The ministry had initially blamed the explosion on a car bomb.

However the interior ministry ruled out the hypotheses of a car bomb, saying it was "probable that the bomb ... was carried by a suicide bomber who died among the crowd."

The device was packed with pieces of metal to cause the maximum amount of harm, it added.

And the circumstances of the explosion, "given the methods that currently prevail in terrorist activities at the global and regional level, clearly indicate" that the bombing was "planned and carried out by foreign elements."

Nermin Nabil, who was injured in the attack, said hundreds of people were still inside the church at the time of the blast and that "if the bishop had finished saying mass two minutes earlier, the bloodbath would have been worse."

In a country suffering from growing sectarian tensions, Mubarak urged Christians and Muslims to unite and confront "terrorism."

He called on the "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," state news agency MENA said.

Refaa al-Tahtawi, spokesman for al-Azhar, Sunni Islam's Cairo-based main institution of learning, denounced the attack and appealed for calm, as did a senior Coptic official, but to no avail.

Nearly 12 hours after the bombing, dozens of Christians were continuing to vent their anger. They clashed with baton-wielding police who had set up a cordon to block access to the church and shouted slogans against Mubarak's regime.

One demonstrator brandished a large cross to which were attached bloody remnants of clothing from the victims.

Protesters shouted "where is the government," blaming it for the incident and saying it was singling out the Copts because of their political views.

Copts account for up to 10 percent of Egypt's 80 million population and often complain of discrimination and have been the target of sectarian attacks.