Sixteen human rights groups are warning that more violence is about to erupt against Egypt's Christians.
Isalmists in the southern part of the country are stirring up anger against the Christian community with charges that its leaders helped engineer President Mohammed Morsi's downfall.
On Tuesday, 10,000 Muslims in the city of Assiut marched through a Christian neighborhood chanting pro-Islamist slogans.
They also defaced churches with spray-painted messages, including one calling Coptic Pope Tawdros "a dog."
Hossam Nabil's jewelry store is located on Youssry Ragheb Street, where the demonstration took place.
"They (the Islamists) will not stop as long as they are left to do as they please without fear of accountability," Nabil warned. "They are many and one day they will trash our stores."
"They (the marchers) run their index finger across their throats to suggest they will slaughter us, or scream Morsi's name in our faces," he said.
The human rights groups are calling on Egyptian authorities to protect the country's Christian minority.