Monsignor Pius Kasha of Syriac Catholic church revealed on Monday that two Catholic priests are among 46 slain worshippers, AFP reports.
"it was a carnage," he said.
"There were less than 80 people inside the church, and only 10 to 12 escaped unhurt", he said adding that two priests were among the dead and that 25 worshippers were wounded, among them a apriest shot in the kidney.
An Iraqi interior official said after Sunday's attack on the church that 46 worshippers had been killed and 60 wounded adding that more than 100 people were inside the Sayidat al-Nejat church in central Baghdad when the hostage-takers stormed in.
He said that seven security forces personnel also were killed and 15 wounded, but did not specify if any were Americans.
A witness said that immediately on entering the cathedral on Sunday, the gunmen shot dead a priest while worshippers huddled in fear.
"They entered the church with their weapons, wearing military uniforms. They came into the prayer hall and immediately killed the priest," said an 18 year old man who witness the scene.
The SITE monitoring group said Monday that Al-Qaeda group The Islamic State of Iraq claimed its fighters were behind the attack.