Since the Egyptian revolution there have been frequent outbreaks of sectarian clashes between Muslims and Copts, usually an outgrowth of local disputes or family feuds but sometimes escalating to the level of attacks on churches or extensive violence. I haven't sought to catalog all of these; they were frequent throughout the Mubarak years as well.
The outbreak in Dashhur over the past week has, however, been on a more serious scale and deserves comment. It started over the usual sort of petty feud: a Coptic laundryman was accused of burning a Muslim's shirt while ironing it; the dispute led to the burning of the laundry shop; molotov cocktails were thrown; one Muslim, apparently a bystander, died; Coptic homes and shops were burned. There were reports of as many as 150 Coptic families fleeing the town, though the Governor says there were only eight. Other reports say 120; it seems clear that there were evictions or voluntary flight of a significant number of Christian families. The Central Security Forces (CSF) moved in and restored order, but remain in place.
This first major sectarian clash since the election of Muhammad Morsi is also a major test of the Muslim Brotherhood's claims to represent all Egyptians, amid Coptic fears of their intentions. There have been criticism that the CSF were slow to move to put down the violence, but now Morsi is saying, “I call on my Muslim brothers and my Coptic brothers to return to each other and for my Muslim brothers to provide security for the Copts.” He has vowed to uphold the law, said "no one can accept that a brother attacks his brother," and urged calm. But platitudes about brotherhood may be of little avail if radical Islamists see his election as an opportunity to pursue old vendettas, personal or economic, against Copts.
Dashhur could provide Morsi with an opportunity for proactive leadership against sectarian violence and give the Muslim Brotherhood an opportunity to demonstrate to Copts that its rhetoric about brotherhood of all Egyptians is real, but so far the response seems mostly to restore order and hope for the best.