Prague (RFE/RL) -- It is very difficult to know how many Christians have left Iraq in recent months.

The U.S. daily "The Wall Street Journal" wrote this week that "precise numbers aren't available, but Iraqi government and church officials estimate as many as 30,000 Christians have left Iraq since a string of church bombings in August, with hundreds more families leaving every week."

Another U.S. daily, "The New York Times," wrote last week that "more than 40,000 Assyrian and other Iraqi Christians are estimated to have fled since war's end" in April last year.

The estimates vary widely because there are no agencies -- Iraqi or international -- that are keeping an accurate count.

The UN's refugee agency says it has noticed an increase in the number of Christians leaving Iraq for Syria. But UN high Commissioner for Refugees (UNHCR) spokeswoman Marie-Helene Verney told RFE/RL from Geneva that the agency does not tally Iraqis by religious affiliation and so has no precise count for the Christians as a group. "It's very hard to put a number," Verney said. "It is clear, however, that [for] the Christian Iraqis in Syria, the caseload is much bigger than the proportion of Christians in Iraq."

Iraqi officials, too, say many Christians are leaving Iraq. But Faris Daniyal, media director of the Iraqi Ministry of Displacement and Migration, called estimates like 30,000 or 40,000 far too large. "It is a very exaggerated number," Daniyal said. "And I don't even call it emigration, but rather traveling until security improves and then they will come back. Because the Iraqi Christians will not abandon their houses and churches, ever."

The Ministry of Displacement and Migration has no estimate of its own for the number of Christians going abroad. Still, if the exact number of Christians leaving Iraq is the subject of debate, the reasons they leave their homes are not. Iraqi Christian leaders say that their community has become a target for intimidation and attacks by Islamic extremist groups.

Violent attacks range from shootings to the simultaneous bombing of five churches in Baghdad and Mosul in August that killed at least 12 people. Mainstream Muslim authorities have condemned the bombings. Preeminent Shi'a cleric Grand Ayatollah Ali al-Sistani called the church attacks "criminal."

Often the Islamist extremist groups target Christian shops or restaurants that sell alcohol. Iraqi Christians are allowed to drink alcohol by their faith and their liquor shops are permitted under Iraq's legal code.

Baghdad's Christian community was particularly shaken earlier this year when unidentified gunmen broke into the home of a liquor-store owner and killed his two sons. The boys, ages 14 and 5, were shot in the head at close range. Other incidents have included the killings of Christian beauty-shop and video-store owners or their relatives or the bombing of their property.

At the same time, many wealthier Christian families fear kidnapping of family members for ransom by criminal gangs. The gangs, which prey on Iraqi families without regard to community, often demand exorbitant sums and sometimes kill their hostages if families cannot raise the full ransom.

William Warda is the head of the culture and information department of the Assyrian Democratic Movement, a Christian political organization in Baghdad. He told RFE/RL that Christians are leaving Baghdad not only to go abroad. He said many are moving from larger cities to safe areas of northern Iraq.

"There is also a migration to the northern provinces," Warda said. "Most of the Assyrian Christians who are in Baghdad are originally from northern Iraq, from Dahouk, Zakho, Amadiyah and Irbil. And in these areas the security situation is better and large numbers of people from Baghdad, Mosul, and Kirkuk are going back to those places where, before, the former regime destroyed their villages and displaced them."

Saddam Hussein's regime tolerated the Christian minority and one of his top aides, Tariq Aziz, was from the Christian community.

But Hussein displaced Christians as well as large numbers of Iraqi Kurds as part of an effort to change the population balance of northern Iraq and bring the region more directly under his control. The government replaced the displaced people with Arab Muslims brought from other parts of Iraq.

Warda said that Christian churches are urging their members to stay in Iraq, where the community has a centuries-old presence. "All the Christian churches are pressing for Christians to stay in their countries of origin, because the true Christian soul is in those countries," he said. "Even his excellency the pope is asking for Christians to stay in the East because the spiritual roots and strength of Christianity is in the East."

Iraq had 1.4 million Christians according to the country's most recent census -- which was conducted in 1987.

The number of Christians in the country today is uncertain, but is often estimated at around 800,000. Large numbers of Christians and other Iraqis who had relatives outside the country left in the 1990s as UN sanctions crippled the economy. Many also fled Hussein's iron rule.

Warda said that, today, Iraq's Christian churches are struggling with economic difficulties with little or no help from the outside. "There is no support for these churches [from outside Iraq]," he said. "They depend on themselves and the donations of the faithful. Every church has its own congregation. Every church has its own collection box. Humanitarian organizations sometimes offer help here and there in small quantities, but not on any regular basis."

Iraq's Christian communities include the Assyrians, the Chaldeans, the Eastern-rite Catholics who recognize papal authority, and the Mandaeans, who follow John the Baptist.