Egypt has experienced many clashes over the years between its Muslim majority and Christian minority, and has always insisted that the conflicts were driven by something  anything  else. A land dispute, a personal grudge, a crime for profit. The official narrative is that these are singular, unrelated crimes.

That is the case since the shooting. Three people were arrested for the attack, which killed six Christians as they left church (Coptic Christians celebrate Christmas on Jan. 7) and a Muslim guard.

“The crime of Nag Hammadi is just an individual crime with no religious motives, just like the crime of raping the girl,” Ahmed Fathi Sorour, the Parliament speaker, said in Al Ahram, a state-owned newspaper.

But local people, commentators, members of Parliament, Christian and Muslim alike, say that the government’s narrow view of the shooting ignores an underlying tension that is roiling society all across Egypt, where an estimated 10 percent of the population of about 80 million is Christian. No matter the gunman’s motive, the attack and subsequent clashes and riots have underscored the religious divide.

“Those calling it an individual crime were not able to explain until now why there was shooting on a group of people leaving church at the time of a big religious celebration, which left six Copts dead,” wrote Salama Ahmed Salama, who is in charge of the editorial board of Shorouk, a daily independent newspaper. “And what was the real motive, especially that the man who committed the crime is among the thugs and hit men, and not from the religiously extreme?”

Nag Hammadi is a city of about 50,000, 40 miles north of Luxor, site of the famed Valley of the Kings. It is a commercial center that hugs the Nile, where the river is wide and the horizon framed by sand-colored cliffs. The streets bustle with taxis, horse-drawn carriages and fruit peddlers. The skyline is pierced by minarets and church towers. About 10 percent of the city is Christian.