(Vatican Radio) Speaking to Catholic charity Aid to the Church in Need, Chaldean Archbishop Amel Nona, said he thought Mosul's last remaining Christians had left now a city which until 2003 was home to 35,000 faithful.
The Christians are among 500,000 thought to have fled Mosul whose overthrow yesterday is now followed by news today (Wed, 11 June) of militant attacks on the Iraqi city of Tikrit 95 miles north of the capital, Baghdad.
Describing reports of attacks to four churches and a monastery in Mosul, the archbishop, 46, said: "We received threats... [and] now all the faithful have fled the city. I wonder if they will ever return there."
The archbishop, who in the ensuing crisis sought sanctuary in Tal Kayf, a village two miles from Mosul, described how the local community were doing their best to provide for crowds of people flooding out of the city and into the surrounding Nineveh plains, where there are a number of ancient Christian villages.
"Up at 5am yesterday [Tuesday, 10 June] morning we welcomed families on the run and we have tried to find accommodation in schools, classrooms and empty houses."
He said: "We have never seen anything like this – a large city such as Mosul attacked and in chaos."
He said that in the 11 years following the 2003 US-led overthrow of Iraq's President Saddam Hussein, Christians in Mosul had declined from 35,000 to 3,000 and that "now there is probably no one left."
The archbishop said the attacks on Mosul began last Thursday (5 June) but were initially confined to the western part of the city.
He said: "The army began bombing the affected areas but later in the night between Monday and Tuesday, suddenly the armed forces and the police left Mosul, leaving it to the mercy of the attackers."
The archbishop questioned reports claiming the militants responsible for the attacks are part of the Islamic State of Iraq and Levant (ISIS), a terrorist organisation linked to Al-Qaeda and in control of key areas of north-west Syria.
He said: "I do not know yet who the group is behind these attacks. Some speak of ISIS, others think other groups are responsible.
"We have to wait until we have a better understanding of the situation. What we do know is that they are extremists, many people have seen them patrolling the streets."