A senior Iraqi Christian is to call on believers to quit the country, after gunmen targeted a church in Baghdad.
Archbishop Athanasios Dawood, who is based in the UK, will make his appeal during a service at the Syrian Orthodox Church in London.
The archbishop has previously criticised the lack of protection for Iraqi Christians.
At least 52 people died as security forces stormed a Catholic church in Baghdad to free dozens of hostages.
A number of gunmen entered Our Lady of Salvation in the city's Karada district during Mass on Sunday 31 October, sparking an hours-long stand-off.
The militants made contact with the authorities by mobile phone, demanding the release of al-Qaeda prisoners and also of a number of Muslim women they insisted were being held prisoner by the Coptic Church in Egypt.
After negotiations failed, Iraqi security forces stormed the building, before the gunmen reportedly threw grenades and detonated their suicide vests.
On Sunday, Archbishop Dawood is expected to advise all Christians to leave Iraq now that al-Qaeda has warned of more attacks there.
The archbishop is also calling on the UK government to grant Christian Iraqis asylum.
Christians - as ethnic Assyrians - have lived in Iraq since the 1st Century, but following the fall of Saddam Hussein, they have become isolated and the Baghdad government has proved unwilling or unable to protect them.
There has been a string of bomb attacks on churches leading many to flee to neighbouring countries.
Church leaders have in the past advised the faithful to stay in Iraq and strengthen their communities.
But such is the insecurity, there are signs this policy may be about to change.
