CAIRO -- Hundreds of Christians and Muslims hurled stones at each other in downtown Cairo on Sunday, hours after Muslim mobs set fire to a church and a Christian-owned apartment building in a frenzy of violence that killed 12 people and injured more than 200.
The deepening religious violence in military-ruled Egypt is exacerbating the lawlessness and disorder of the country's bumpy transition to democracy after three decades of autocratic rule under former President Hosni Mubarak was brought to an end in February.
Muslim youths attacked a large crowd of Coptic Christian protesters marching from the headquarters of Egypt's general prosecutor to the state television building overlooking the Nile, said Christian activist Bishoy Tamri. TV images showed both sides furiously throwing stones, including one Christian who held a large wooden cross in one hand while flinging rocks with another.
Scores were injured, but an army unit securing the TV building did nothing to stop the violence, Tamri said.
Hours earlier, mobs of ultraconservative Muslims attacked the Virgin Mary Church in the slum of Imbaba on the opposite side of the Nile. The attack was fueled by rumors that a Christian woman married to a Muslim man had been abducted by the church. Residents said a separate mob of youths armed with knives and machetes attacked an apartment building several blocks away with firebombs.
"People were scared to come near them," said resident Adel Mohammed, 29, who lives near the Virgin Mary Church. "They looked scary. They threw their firebombs at the church and set parts of it ablaze."
The military deployed armored vehicles and dozens of troop carriers to cordon off a main street leading to the area. They halted traffic and turned away pedestrians. Men, women and children watching from balconies took photos with mobile phones and cheered the troops.
Islamic clerics denounced the violence, sounding alarm bells at the escalating tension during the transitional period following Mubarak's Feb. 11 ouster by a popular uprising.
"These events do not benefit either Muslim or Copts," Ahmed al-Tayyeb, the sheik of al-Azhar, told the daily Al-Ahram.
Interfaith relationships are taboo in Egypt, where the Muslim majority and sizable Christian minority are both largely conservative. Such relationships are often the source of deadly clashes between the faiths.
During the 18-day uprising that ousted Mubarak, there was a rare spirit of brotherhood between Muslims and Christians. Each group protected the other during prayer sessions in Cairo's Tahrir Square, the epicenter of the revolution.
But in the months that followed, there has been a sharp rise in sectarian tensions, fueled in part by a movement of ultraconservative Muslims known as Salafis who have become more active in Egypt.
(This version CORRECTS that one church was burned in overnight attack).)