Cairo, Egypt (CNN) -- Egyptian authorities have rounded up 156 people in connection with this week's deadly protests over plans to build a church near Cairo, the government announced Thursday.
Those arrested have been ordered held for 15 days while the investigation into Wednesday's clashes continues, Egypt's official Middle East News Agency reported.
Police battled about 150 demonstrators outside a government building in the Cairo suburb of Giza on Wednesday. Police turned to tear gas to break up the melee, while protesters responded with Molotov cocktails. The clashes left a Christian protester dead.
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.
CNN's Ben Wedeman contributed to this report.