By Magdi Abdelhadi
BBC Arab affairs analyst
The recent attacks on Christian churches in Iraq are believed to be the first of their kind in the country's history.
Iraq's Christian community - one of the oldest in the world - has generally been spared the fear of persecution that has plagued many other such communities in the Middle East as a result of the rise in belligerent Islamic movements.
Bombers attacked five churches in Iraq on 1 August
This is also the first time Christian churches have been targeted since the fall of the Baath regime in April last year.
It raises the question of whether the attacks are the work of known Iraqi insurgents and whether they could represent a new tactic by these groups, who are waging war on the multinational troops and the interim government under the banner of Islam.
The power vacuum created by the fall of Saddam Hussein last year saw the emergence of various Islamist groups.
Some are home-grown while others are believed to be foreign imports related to the al-Qaeda network.
But not all of them pursue their goals by means of violence.
Sunday's bombings were not the first time Iraqi Christians have come under attack over the past 14 months.
Several Christian merchants have had their shops burnt down because they sold alcohol.
Such vigilante violence is believed to be the work of local Iraqi Islamists, including the followers of radical Shia cleric Moqtada Sadr.
Their aim is to enforce an Islamic code of behaviour, which includes a ban on alcohol and the promotion of the Islamic dress code, ie the veil for women.
These groups share this agenda with other Islamists operating in the Middle East.
Ultimately, they hope to create a society ruled by Islamic Sharia law.
Co-ordinated suicide attacks have become the hallmark of an organisation known as al-Tawhid and Jihad, which is led by a Jordanian called Abu Musab al-Zarqawi.
The group, which is also believed to be an al-Qaeda affiliate, has claimed responsibility for several spectacular multiple suicide bombings which killed many Iraqis, mainly policemen.
A plot to foment sectarian violence between Shia and Sunni Muslims has also been attributed to the same man.
The ideology of groups such as al-Zarqawi's is not fundamentally different from that of various Islamist organisations in the region.
But his approach and tactics are similar to those of al-Qaeda: both are pursuing a global jihad against the perceived enemies of Islam, wherever they are.
For them, Iraq has become the latest, and probably the most important, battlefield.
The website of the group depicts the current conflict in Iraq as a war between Muslims and "the Crusaders".
Visitors are greeted by the following caption:
"Coming soon - a film depicting the slaughter of the Bulgarian pig, whose government refused to comply with the demands of the Mujahedeen.
"It is a government in alliance with the Americans, and its troops have taken part in the Crusade against Iraq."
The website also posts a video sequence showing the killing of another hostage, a Korean worker.
It says: "This infidel pig worked for a Christian company that provided supplies for the American army and donates 10% of its revenues to missionary work in Muslim countries."
It says that the Korean worker "had studied Christian theology and was hoping to become a missionary in the Arab World".
According to this mindset, the conflict in Iraq is a religious war and the Christians, regardless of where they come from, can easily be cast in the role of the enemy.