The death toll from Saturday morning's bombing outside a church in the city of Alexandria has risen to at least 21, with dozens more injured, security said. A preliminary report published by Egypt's Ministry of Interior late Saturday said that they believe the attack was a suicide bomber, not a car bomb as initially reported. Security has been tightened in the northern Mediterranean city and across the country to prevent further clashes with police. An unknown number of Egyptian Coptic Christians have been arrested after angrily confronting police near the scene of the explosion hours after it had happened. Elsewhere in the country, Copts have taken to the streets of Cairo to express their anger. The demonstrators were holding large wooden crosses and pictures of Jesus before being cornered by the police and forced to leave to nearby streets in the predominantly Coptic neighborhood of Shobra. The Egyptian government however, has declared that the explosive device was locally made, but has not ruled out the possibility of “foreign hands” being involved in the attack, referring to al-Qaeda in Iraq's network that had sent threats over the past two month of attacking churches in the country over what they said were two women being held “hostage” by the Coptic Church of Alexandria after the women had converted to Islam. Egypt's President Hosni Mubarak addressed the nation early Saturday, denouncing the attack and calling on Egypt's Christians and Muslim to unite in the face of terrorism. “This terrorist act has shaken the conscience of the nation. The blood of our children will not be lost and we will cut off the hand of terrorism,” Mubarak said in his televised address. The president also pointed to foreign involvement in the attack and promised to “cut the hand of terrorism.” The funeral of those killed took place on Saturday in the presence of Alexandria's Governor Adel Labib, who according to Egyptian blogs was attacked by angry locals. At least 1,000 worshipers had attended the Saints Church's New Year's Eve mass. One priest at the church told local press that the death toll could have been much higher if the bomb went off few minutes later as more people were leaving. Most of the injured were Muslims, local reports said. BM