A leader of al Qaeda in Iraq has been sentenced to death for the killing of Chaldean Catholic Archbishop Paulos Faraj Rahho, whose murder in March drew worldwide condemnation, the Iraqi government said on Sunday.

The Iraqi Central Criminal Court imposed the death sentence on Ahmed Ali Ahmed, known as Abu Omar, Iraqi government spokesman Ali al-Dabbagh said in a statement. Rahho, the archbishop of the northern Iraqi city of Mosul, 390 km (240 miles) north of Baghdad, was abducted on Feb. 29 after gunmen attacked his car and killed his driver and two guards. His body was found in a shallow grave two weeks later.

At the time, Prime Minister Nuri al-Maliki blamed al Qaeda and vowed to bring the bishop's killers to justice. His Shi'ite Muslim-led government has been accused by members of Iraq's dwindling Christian minority of not doing enough to protect them from violent persecution.

Chaldeans belong to a branch of the Roman Catholic Church that practices an ancient Eastern rite and form the biggest Christian community in Iraq.

Dabbagh said Ahmed was a leader of Sunni Islamist al Qaeda and had been sought for his involvement in a number of "terror crimes against the people of Iraq".

He described Rahho as an advocate of peace and tolerance among Iraqis. When Rahho's body was found on March 13, police said it was not clear whether the 65-year-old clergyman, known to be in poor health, had been killed or died of other causes.

A number of Christian clergy have been kidnapped and killed and churches bombed in Iraq since the 2003 U.S.-led invasion. A former archbishop of Mosul, Basile Georges Casmoussa, was kidnapped in 2005 but later released after a day in captivity.