Iraq blasts
Iraqi Christians attend a Christmas Eve mass at St Joseph Chaldean Church in BaghdadReuters

A car bomb has killed at least 15 people and injured 31 during Christmas celebrations in the Iraqi capital Baghdad.

Most of the victims are Iraqi Christians, according to multiple reports.

The explosion took place near a church in Doura town as the victims were finishing their morning service.

Christian venues on special occasions have often been kept on high alert in the restive nation as communal violence remains widespread, after the fall of dictator Saddam Hussein.

Rights groups had warned about possible violence during the Christmas.

"There's a culture of fear that has developed there that makes it hard for people to want to go to church to express their faith, especially at the holiday season. These extremist groups desire religious cleansing and they're increasing in number particularly in northern Iraq," David Curry, the chief of Open Doors USA told on Christmas Eve.

The country's Christian population, often targeted by al-Qaida and other militant groups, has dwindled in recent years from one million to nearly 300,000.