Iraq's prime minister says a deadly attack on a Catholic church in Baghdad was an attempt by insurgents to pull Iraq back into sectarian fighting.

Prime Minister Nouri al-Maliki said in a statement Monday that the attackers also sought to drive more Christians out of the country.

An Iraqi police officer stands guard at the scene of a car bomb attack in front of an Assyrian Catholic Church in Baghdad on Monday. (Khalid Mohammed/Associated Press)

At least 58 people, including a priest, died after Iraqi security forces stormed a Baghdad church where militants had taken an entire congregation hostage for several hours, Iraqi officials said Monday.

The incident began when militants wearing suicide vests and armed with grenades attacked the Iraqi stock exchange at dusk Sunday before turning their attention to the nearby Our Lady of Deliverance church — one of Baghdad's main Catholic places of worship — taking about 120 Christians hostage.

It was not immediately clear whether the hostages died at the hands of the attackers or during the rescue late on Sunday night in an affluent neighbourhood of the capital. Roughly 4.5 hours passed between the car bombing and the end of the siege at 10 p.m.

Officials said the bloodbath left at least 58 people killed and 78 wounded, more than the total number of hostages.

At least one priest and 12 policemen were among the dead. It is believed at least five bystanders were killed by the blasts outside before the massacre began inside.

Pope Benedict XVI denounced the "ferocious" attack and called for renewed international efforts to broker peace in the region.

Rescue operation 'not professional'

A Christian member of parliament on Monday described the Iraqi rescue operation as "not professional," saying "it was a hasty action that prompted the terrorists to kill the worshippers."

"We have no clear picture yet whether the worshippers were killed by the security forces' bullets or by terrorists, but what we know is that most of them were killed when the security forces started to storm the church," Younadem Kana said.

Video footage from an American drone that was overhead during the attack showed a black plume of smoke followed by flashes from inside the building before what appears to be soldiers going in. U.S. forces often supply air support to Iraqi forces conducting operations on the ground, feeding them video footage of what American drones see from the air.

There were conflicting accounts about the number of attackers involved in the assault, with Baghdad military spokesman Maj. Gen. Qassim al-Moussawi saying Sunday night that security forces killed eight, while the U.S. military said between five and seven died.

Two police officers on the scene, however, said only three attackers were killed and another seven arrested afterward.

Outside the Syrian Catholic church Monday morning, Raed Hadi leaned against his car on top of which rested a casket holding the body of his cousin, who was killed in the siege. Hadi was waiting for the police to let him onto the church grounds to bury his relative. He railed against Iraqi authorities.

"It was a massacre in there and now they are cleaning it up," said Raed. "We Christians don't have enough protection .… What shall I do now? Leave and ask for asylum?"

Police pushed back onlookers from around the church by erecting a barbed wire fence but residents and people from the Christian community claimed that it was too little, too late.

A cryptically worded statement posted late Sunday on a militant website allegedly by the Islamic State of Iraq appeared to claim responsibility for the attack. The group, which is linked to al-Qaeda in Iraq, said it would "exterminate Iraqi Christians" if Muslim women in Egypt were not freed.

'Absurd violence'

During a holiday blessing Monday from his studio overlooking St. Peter's Square, Benedict said he was praying for the victims "of this absurd violence, made more ferocious because it was directed against unarmed people gathered in the house of God."

He called for new international and national efforts to end violence, and said he wanted to renew his solidarity with the Christian community in the Middle East and encourage the faithful there to "be strong and safe in hope."

"Faced with such brutal episodes of violence which continue to tear apart the people of the Middle East, I want to renew again my heartfelt appeal for peace," Benedict said.

His appeal came just a week after he closed a two-week meeting of Mideast bishops dedicated to supporting the minority Christian flock in the largely Muslim region. During the meeting, Iraq's bishops in particular denounced how their faithful were disproportionately targeted by violence.

Iraqi Christians, who have been frequent targets for Sunni insurgents, have left in droves since the 2003 U.S.-led war.