ISIS has reportedly been converting churches into prisons in Mosul, an Iraqi city that was once largely a Christian community.
According to reports, detainees have been sent to the ancient Chaldean church of the Immaculate Conception.
"The jihadists of the Caliphate have occupied the churches, including those which are very ancient," said Rebwar Audish Basa, Procurator of the Order of St. Anthony sant'Ormisda of the Chaldeans.
"Among the concerns that plague us there is also that of those who fear that a possible military offensive for the liberation of Mosul could inevitably lead to consider churches as targets to hit, since they have become logistic bases of the jihadists. And of course, the destruction of old churches would be an irreparable damage and loss."
ISIS took control of Mosul in June, forcing Christians in the city to convert to Islam, pay a tax or be killed for their faith. About 60,000 Christians lived in the city before 2003.
In response, a U.S.-led coalition has launched airstrikes at the terrorists. In November, Radwan Taleb al-Hamdouni, the top ISIS leader in Mosul, was killed by an airstrike.
"It is much harder now than when we started for Daesh to assemble forces in strength to travel in convoys and to launch concerted attacks," said Secretary of State John Kerry. "No large Daesh unit can move forward aggressively without worrying about what will come down on it from the skies."
Publication date: December 3, 2014