VATICAN CITY (AP) -- A Roman Catholic archbishop in Mosul, Iraq, has been kidnapped, the Vatican said Monday.

It identified the kidnapped man as Archbishop Basile Georges Casmoussa, 66, of the Syrian Catholic Church, one of the branches of the Roman Catholic Church.

"The Holy See deplores in the firmest way such a terrorist act," a Vatican statement said, demanding that he be freed immediately.

According to reports from Baghdad, Casmoussa was walking in front of his church in Mosul's eastern neighborhood of Muhandeseen when he was abducted.

Mosul is a northern Iraqi city that in recent months has been a hotspot of violent insurgency.

The reason for the kidnapping was unclear, but Christians -- tens of thousands of whom live in and around Mosul -- have been subjected to attacks in the past.

Christians make up just 3 percent of Iraq's 26 million people. The major Christian groups in Iraq include Chaldean-Assyrians and Armenians. There are small numbers of Roman Catholics.

Officials estimate that as many as 15,000 Iraqi Christians have left the country since August, when four churches in Baghdad and one in Mosul were attacked in a coordinated series of car bombings. The attacks killed 12 people and injured 61 others.

Another church was bombed in Baghdad in September.

By Bassem Mroue