The January attack on a church in Alexandria killed at least 21 people [EPA]

January 1, 2011 - A car-bomb attack hits a church in Alexandria, killing at least 21 people and prompting Christians to take to the streets in protest.

After the explosion, enraged Christians emerging from the church clashed with police and stormed a nearby mosque, prompting fights and volleys of stone-throwing with Muslims.

November 24, 2010 - Clashes between riot police and hundreds of Christians protesting after construction of a church is halted in Cairo takes a communal turn as dozens of Muslims join the violence.

Two Christians are killed by the violence, and more than 150 people are detained.

November 1, 2010 - The Islamic State of Iraq, the al Qaeda-linked group which claimed responsibility for an attack on a Baghdad church, threatens attacks on the Christian church in Egypt over its treatment of women the group said the church was holding after they had converted to Islam.

April 11, 2010 - Egyptian Initiative for Personal Rights, an Egyptian group, issues a report saying the number of cases of religious violence rose between 2008 and 2009 and calls for the prosecution of offenders to prevent a further escalation.

January 6, 2010 - Six Christians and a Muslim policeman are killed in a drive-by shooting on the eve of the Orthodox Coptic Christmas outside a church in the southern town of Nagaa Hamady.

The shooting leads to protests. Some Christian and Muslim homes and shops are set a blaze in the violence.

May 10, 2009 -  A small homemade bomb explodes near a church in Cairo but no one is hurt.

The device damages a car and a second one is found and detonated by police in the same area in the northeast of the capital, officials said.

Source: Agencies