(WaPo)- Security officials said the militants, who were allegedly linked to al-Qaida in Iraq, were on the phone with Iraqi authorities demanding the release of imprisoned female insurgents when security forces stormed the building. The standoff began at dusk when the militants attacked the nearby Iraqi stock exchange, officials said. Police then chased the insurgents toward the Our Lady of Deliverance church one of Baghdads main Catholic places of worship. Worshippers inside were listening to a Bible reading when the gunmen burst in, said parishioner Marzina Matti Yalda. As we went outside the hall to see what was happening, gunmen stormed the main gate and they started to shoot at us, Yalda said. Many people fell down, including a priest, while some of us ran inside and took shelter in a locked room. We were packed together as we waited for the security forces to arrive. A U.S. Army spokesman, Lt. Col. Eric Bloom, said at least 19 people were killed seven hostages, seven Iraqi security troops and five militants. He said the assailants were wearing suicide vests and armed with grenades. As many as 30 people were wounded, including a priest and a nun, he said. Iraqi military officials said the death toll was at least nine, while police and medical officials put it as high as 37. The figures could not be immediately reconciled. There were also conflicting reports about the militants fate. An Iraqi police official put the number of insurgents at 10 and said all were captured. And Baghdad military spokesman Maj. Gen. Qassim al-Moussawi said security forces killed eight attackers, while the U.S. military said between five and seven attackers died. Different figures are normal immediately following such attacks. Iraqi Defense Minister Abdul-Qadir al-Obeidi said the terrorists were planning to murder the highest number of hostages. Across Iraq, security forces were alerted to new threats against Christians. Al Qaedas Iraqi affiliate, the Islamic State of Iraq, claimed responsibility for the attack on the dirty place of the infidel which Iraqi Christians have long used as a base to fight Islam.