Egypt's Christians have been stunned by a drive-by shooting in which masked gunmen sprayed a wedding party outside a Cairo church killing four people, including two young girls.
The attack raised fears of a new insurgency by extremists after the military's removal of the president and a crackdown on Islamists.
Several thousand Christians gathered for the funeral of the four members of a single family killed, as the government and religious leaders condemned the attack.
Egypt has seen an increase in attacks by Islamic radicals since the military removed Islamist president Mohammed Morsi and launched a heavy crackdown on his Muslim Brotherhood and its allies. The targets have mainly been security forces and Christians, whom Islamists blame because of their strong support of Morsi's overthrow.
In Sinai, suspected jihadi fighters have stepped up attacks on soldiers and police. In rural provinces of the south, there has been a wave of mob attacks led by extremists against churches, which have been burned and looted.
But the bloodshed in Cairo's Warraq district was the first such violence in the capital, a direct shooting against Christians.
The military-backed interim prime minister, Hazem el-Beblawi, pledged the Sunday night attack would "not succeed in sowing divisions between the nation's Muslims and Christians."
The top cleric at Al-Azhar, the world's primary seat of Sunni Islamic learning, called the shooting "a criminal act that runs contrary to religion and morals."
In a brief statement, an umbrella group of Islamist parties, including Morsi's Muslim Brotherhood, which have led a campaign of protests against the July 3 coup, also condemned the attack.
Christians, mostly from the Coptic Orthodox Church, make up about 10% of Egypt's population of 90 million. They have long complained of discrimination by the country's Muslim majority. Now they also have been increasingly targeted in a militant backlash after Mr Morsi's removal.
Speaking on Egypt's Orbit TV channel, Nageh Ibrahim, a former Islamic militant who has foresworn violence, said extremists are resorting to "mass punishment" against Christians and using attacks on them to pressure the government and the Coptic Church, hoping to "break the alliance between them."
Sunday's shooting also harkened back to an Islamic militant insurgency in the 1980s and 1990s in which extremists waged a campaign of attacks on police, Christians and foreign tourists, trying to topple the government.
Many fear a revival of that campaign. The army and security forces are fighting what in effect has become a full-fledged insurgency in the northern part of the strategic Sinai Peninsula, where militants carry out attacks almost daily since Morsi's fall.
High-profile attacks blamed on militants have begun to creep into Cairo, the capital and home to some 18 million. In September, the interior minister survived an assassination attempt by a suicide car bombing in Cairo. Earlier this month, militants fired rocket propelled grenades on the nation's largest satellite ground station, also in Cairo. The Interior Ministry reports near-daily discoveries of explosives planted on bridges and major roads.