A leading Christian in Iraq is speaking out about conditions there — and, not surprisingly, the picture he paints is grim:

An Anglican clergyman in Baghdad, who has seen his flock murdered and forced into exile by Muslim extremists, says Christians there are worse off now than under Saddam’s rule and are probably suffering more than any time in history.

The Rev. Canon Andrew White, an Anglican priest known as the “Vicar of Baghdad,” speaks to 60 Minutes’ Scott Pelley for a segment on the persecution of Christians in Iraq to be broadcast this Sunday, Dec. 2, at 7 p.m. ET/PT.

“There’s no comparison between Iraq now and [under Saddam],” says White. “Things are the most difficult they have ever been for Christians – probably ever in history,” he tells Pelley, referring to the nearly 2,000 years of Christian history in the area. That’s because White estimates that 90 percent of Iraq’s Christians, once thought to number over a million, have either fled or have been murdered by Islamic extremists during the religious civil war.

That includes his own church leaders and most of the men of his parish. “They are mainly killed. Some are kidnapped,” says White. “Here in this church, all of my leadership were originally taken and killed.” Their bodies were never recovered. “This is one of the problems. I regularly do funerals here, but it’s not easy to get the bodies,” White tells Pelley.

White invited 60 Minutes cameras to an underground Baghdad service for what’s left of his congregation, mostly the old, the ill and those who cannot afford to flee. The purge is almost complete in the Dora neighborhood of Baghdad, once a Christian stronghold, and the recent surge of American troops also has stemmed some of the violence. “I don’t see a lot of [Christian murder victims] anymore,” says Army Col. Rick Gibbs. “But when we first arrived, we saw lots of that. It would not surprise my soldiers to walk down a street on patrol and see three or four bodies laying in the street with a bullet behind their head,” says Gibbs.

At the height of the violence, churches were bombed and the Army did not guard them, Gibbs says. “[Christians] feel that if we are overtly protecting the churches, that someone underground covertly will come in and murder the Christians because they are collaborating with the U.S. forces,” Gibbs tells Pelley.