Grief and anger have gripped Egypt's Coptic Christian community after a deadly New Year's Eve suicide bombing attack on a church.
Christian protests in Alexandria and Cairo have led to clashes with security officials and Muslims. Christians said they're fed up with official discrimination and the Egyptian government's failure to protect them.
President Barack Obama, Pope Benedict XVI, and world leaders have condemned the attack that killed 21 worshippers, and wounded nearly 100, at a midnight mass in Alexandria. The attack came on the heels of several deadly attacks against Christians in Iraq during the Christmas season.
Religious rights watchers said it's more proof that Christians in the Middle East are under increasing pressure.
Egyptian authorities were trying to determine if homegrown Islamic radicals were involved in the bombing. They're also investigating whether al Qaeda-backed outsiders, possibly from Iraq, sneaked into Egypt to commit or coordinate the bombing.
Al Qaeda terrorists and Muslim militants have killed an estimated 100 Iraqi Christians in the last two months.
Some fear this horrible trend will continue against Christians in other parts of the Islamic world.
"They have been targeted for extermination in places where they have been systematically oppressed for a long time," said Dr. Carl Moeller, president of Open Doors USA.
On Sunday, Christian protestors took to the streets in three Egyptian cities.
"All these people murdered, what have they done?," one person cried out. "They were just celebrating a new year, praying in a house of God."
Much of the protestors' anger was aimed at the police and government, who they said don't do enough to protect Egypt's Christian minority.
Egyptian President Hosni Mubarak blamed outside terrorists and spoke of Muslim/Christian unity.
"Terrorists are not going to succeed in threatening Egypt and threatening the unity of the Muslims and Christians living side by side in Egypt," Mubarak said.
Egypt's top Muslim cleric, Ahmed al-Tayeb, appeared with the spiritual leader of the nation's Orthodox Coptic Christians to say all Egyptians of all religions need to stay united.
Pope Benedict said the attack in Egypt, just like those on Iraqi Christians, "offends God and the whole of humanity."
"We need to stand alongside our brothers and sisters around the globe that are fighting against this sort of violence," Moeller said.
Meanwhile, many of Iraq's Christians have left the country. In 2003, an estimated 1.4 million Christians lived in Iraq. Less than 500,000 remain.