The Egyptian government vowed on Sunday to punish the perpetrators of the deadly church attack in the coastal city of Alexandria on New Year's Eve, while fears of sectarian tension in Egypt flared up.

The suicide bombing in Alexandria is a treacherous crime aimed at crabbing Egypt's stability and security and creating sectarian strife in the Egyptian street, said Minister of Legal Affairs and Parliamentary Councils Mofeed Shehab in a statement.

Egyptian riot police clash with Christians in front of the Coptic Orthodox church after a bomb exploded at the All Saints Church in Egypt's northern city of Alexandria, Jan. 1, 2011. [Xinhua]

Hundreds of Copts took part in marches Sunday in Cairo and Alexandria, condemning the church explosion and protesting against government's failure to protect their community. Clashes between hundreds of outraged young Christian protesters and the Egyptian police intensified near the church on Saturday.

"We will sacrifice our blood and soul for the Christ," chanted the protesters. Meanwhile, many Coptic worshippers condemned terrorism and urged the government to act responsibly and work hard to punish the perpetrators.

"This is not fair. The government has to find us a solution to this and stop acting that cool and referring everything to meaningless excuses," said a Coptic worshipper.

The Grand Imam of Al-Azhar Ahmed el-Tayyeb, Egypt's top Muslim cleric, paid a visit to Pope Shenouda III, head of Coptic Orthodox Church in Cairo, on Sunday and expressed his condolences over the fall of innocent people in the attack.

The meeting didn't cool down the anger of Copts, who continued their protest although Pope Shenouda called on all Copts to be calm and exercise self-restraint.

It was reported that protesters attacked the vehicles of the Grand Imam until the police interfered.

Copts held mass on Sunday at the Al-Qiddeseen Church in Alexandria, mourning the victims of the blast, which killed 21 and wounded 100 others. Tears and pains overwhelmed the worshippers, who lit candles and prayed for their fellows killed in the tragedy.

The Al-Qiddeseen Church officially denounced the attack and reaffirmed that it was not sectarian, appealing for patience and calm.

"Now we're quite certain that it has nothing to do with sectarianism, especially that we have little sectarianism in Egypt, " said Bishop Makar, spokesman of the church, stressing that Muslims and Copts have always lived in harmony in Egypt.

Until now, no group has claimed responsibility for Saturday's bombing, which came when Christians left Al-Qiddeseen Church after attending the New Year's Eve mass.

Mofeed Shehab said in the statement that it is still too early to determine the identity of those behind the attack and the way it was carried out, blaming foreign elements for planning and executing the attack.

Egyptian President Hosni Mubarak in his televised speech on Saturday stressed that the authorities had evidence that foreign elements were involved in the bomb blast, pledging that the traitors would never go unpunished.

At the same time, some Egyptian analysts said al-Qaida's cell should be behind such crime, predicting similar attacks in the future.

"The blast has al-Qaida hands in it, because all the terrorist operations that took place in Egypt since 2003 has never been with similar professionalism," said Amr El Chobeki, a researcher at the Al-Ahram Center for Political and Strategic Studies.

Alexandria's bombing came almost two months after an attack on a church in central Baghdad that left 53 dead.

Al-Qaida's Iraqi branch claimed for the attack and threatened to attack Egyptian Copts if their church didn't free two Christian females, rumored to be imprisoned in their monasteries for having converted to Islam.

"Al-Qaida is trying to build a terrorist cell in Egypt," added El Chobeki.

"Al-Qaida as an entity has been divided into branches in Egypt, Yemen and Morocco," Egyptian strategic expert Hossam Suilem further explained, adding that despite there is no relations between these smaller branches and al-Qaida itself, they adopt the same ideology as al-Qaida.

Coptic Christians account for about ten percent of Egypt's total population of nearly 80 million. Tensions between Muslims and Coptics have sharpened in Egypt for a number of reasons including religious conversions.

Christians often complain that they are discriminated against in the Islamic country, saying they are not granted the same freedom of building churches as Muslims building mosques.

In late November last year, hundreds of Egyptian Coptic Christians clashed with police in Giza governorate to protest against the freeze of building a church, leaving one protester killed.

A few days before the November clash, Muslims set fire to some houses owned by the family of a Coptic man who was said to have an affair with a Muslim girl in southern Egypt.

The Egyptian government has been appealing and striving to achieve unity between the Muslim majority and the Coptics in the country.