A Christian protester was killed and dozens others were wounded Wednesday in violent clashes with police that erupted over permission to build a church here.
Egyptian police fired tear gas. The 150 demonstrators answered with Molotov cocktails.
In the aftermath of the melee, the ground in front of a government building in suburban Giza was littered with rocks and knocked-over potted plants.
An Interior Ministry spokesman said 93 people were arrested.
Tensions have been running high between Egypt's Muslim majority and minority Christians who make up about 9 percent of the people.
Copts, who are adherents of an Egyptian sect of Christianity, complain of discrimination, including the lack of freedom to build houses of worship. The government denies those accusations.
However, the U.S. Commission on International Religious Freedom has expressed concern that the Egyptian government and media have deliberately promoted sectarian friction ahead of parliamentary elections scheduled for December.
"We've seen a clear uptick in recent weeks of incitement coming from media outlets and clerics espousing sectarian hatred and violence," said Leonard Leo, chairman of the independent, bi-partisan commission. "This kind of rhetoric goes too far and stokes the fire of extremists looking for ammunition to justify violent acts against religious minorities."
The commission said that earlier this month, ten Coptic Christian homes and several businesses were burned and looted in Qena province in southern Egypt following rumors of a romantic relationship between a Christian man and Muslim woman.
Security officials imposed a curfew and arrested several Muslims, the commission said.
"Sure! We get killed because we want to build a church in their land BUT, they have the balls to build a mosque where they killed all those people and be animal enough to ask for 911 money. What a mentality these idots have!"