Islamic State fighters are the "grandsons of Satan" according to survivors of the torture and slaughter in Mosul in Iraq.
Iraqi forces are trying to drive ISIS from the Nineveh plains, which has for centuries been a traditional homeland for Christians and Yazidis in Iraq.
The liberation of Iraq is being taken cautiously because of the large numbers of vulnerable civilians who are still alive but are effectively being held hostage by the brutal Islamist fighters.
In a report from Iraq by the BBC's Richard Galpin, who visited some of the few districts of Mosul that have been freed from ISIS, Basma al-Saoor, a survivor who visited a church and also the rubble of her former home, said: "They [ISIS] are the grandsons of Satan."
When ISIS took Karamles and nearby villages two years ago, civilians were ordered to leave, convert to Islam or be killed. Nearly everyone fled.
Father Paul Thabet, the priest at Saint Addai church in Karamles, showed Galpin how statues of Jesus, the Virgin Mary and child angels had all been decapitated, the altar shot through with bullets and a priest's tomb desecrated.
Father Thabet called for those responsible to face justice and fears that good relations between Muslims and Christians in the region have been destroyed beyond repair.
Galpin reports that beside Iraqi army solders, the troops taking part in the fighting against ISIS include Shia militias, Peshmerga Kurdish troops, Christian militias and some Sunni tribesmen.
He reports that casualties are high. Former Iraqi army and intelligence officers are believed to be helping ISIS stay in Mosul and they have been deploying suicide bombers and snipers to attack Iraqi forces as they try to advance.
"It was never going to be easy to dislodge Islamic State from Mosul, but unless the militants suddenly collapse or cut and run, it looks like it is going to be a long, costly battle," he says.