An al-Qaeda-linked group has claimed responsibility for an attack on a Catholic church in the Iraqi capital, which resulted in the deaths of 58 people.
The Reuters news agency reported the death toll on Monday, a day after attackers stormed the Our Lady of Salvation church in the Karrada neighbourhood of central Baghdad.
The assailants took more than 100 people hostage in a standoff that ended after police stormed the church two hours later. At least 25 of those killed were hostages.
"Right from the very beginning their phone calls were fully intercepted and we strongly believe there were non-Iraqi people among the group. We will investigate their nationalities," Abdul Qader al-Obeidi, the Iraqi defence minister, said.
The kidnappers were demanding the release of al-Qaeda prisoners from Iraqi and Egyptian jails, Al Jazeera's Rawya Rageh reported from Baghdad.
Al-Baghdadiya television station said it had received a phone call from someone claiming to be one of the attackers, who demanded the release of all al-Qaeda prisoners in Iraq and Egypt.
That person spoke classical Arabic, "perhaps an attempt to conceal his identity," Rageh said.
The Islamic State of Iraq, a group which is linked to al-Qaeda, later claimed responsibility for the attack in a statement posted online after the incident.
The group alleged that female Muslims were being held against their will in Coptic Christian monasteries in Egypt.
"[There is] some sort of Egyptian involvement there, but authorities are not confirming that," our correspondent reported.
Major-General Qassim al-Moussawi, a Baghdad security spokesman, told the Reuters news agency on Sunday that the operation "has finished successfully".
Sunday's attack began with at least one loud explosion followed by bursts of gunfire. Streets around the church were quickly cordoned off.
Earlier the assailants, wearing suicide vests, killed two guards who tried to stop them from raiding the stock exchange building.
After battling security forces at the stock exchange, the men fled to the nearby church, where they held the building's construction and cleaning crew hostage inside.
Abdullah Hermiz, the head of Christian Endowment, a state body that oversees Iraq's chruches, told the Associated Press news agency that only part of the building was under construction and that Sunday services were being held as usual in another part of the church.
"When they were about to leave and heard the shooting outside and because of the scary situation, some ran outside the church while others remained inside," he said.
Our correspondent said that according to the US military the attackers were al-Qaeda operatives, based on their "tactics, techniques and procedures".
Pope Benedict condemned on Monday the attack in remarks to pilgrims gathered to hear his prayer in St Peter's Square for the Catholic All Saints' Day holiday.
"I pray for the victims of this senseless violence, made even more ferocious because it struck defenceless people who were gathered in the house of God, which is a house of love and reconciliation," he said.
Nouri al-Maliki, the Iraqi prime minister, also condemned the siege, saying it was an attempt to drive more Christians out of the country.
"The cowardly, terrorist crime at Our Lady of Salvation Church in Baghdad last night shook us and all honorable Iraqis around the world," he said.
"Those with deviant thoughts from al-Qaeda and their allies belonging to the followers of the ousted regime targeted our Christian brothers in a terrorist crime that aims at undermining security and stability, inciting strife and chaos and sending Iraqis away from their home."
Lieutenant-Colonel Eric Bloom, a US army spokesman, said about 100 people had been in the church when the attackers came in, but some 19 of them managed to escape.
"They [Iraqi forces] went into the church and rescued the hostages," Bloom said. "They have control of the church".
He said US forces provided air support but did not have soldiers on the ground going into the church. Iraqi Special Forces stormed the church around 9pm.
Bloom later told Al Jazeera that the incident was a "robbery gone wrong".
"We've seen them resort to robbery to get financed. It has been very challenging for them to get outside financing, so they are resorting to small, petty crimes to try to finance themselves".
Source: Al Jazeera and agencies