Many shops were damaged in clashes that followed the killings earlier in January
By Yolande Knell
BBC News, Cairo
Worshippers arriving for mass at St Mary's Church in central Cairo say they were shocked but not surprised by a deadly attack against Coptic Christians in southern Egypt earlier this month.
"Copts have been suffering for a long time," comments Magda accompanying her teenage son to the service.
"There have been a lot of tensions between Christians and Muslims, particularly in Upper Egypt, and a lot of attacks."
"What happened in Naga Hamady has opened the situation up to the outside world."
Six Copts were killed in a drive-by shooting in the busy town, 60 km (37 miles) from Luxor, after they left a late-night mass on 6 January, the eve of the Coptic Orthodox Christmas. A Muslim policeman was also killed.
There are frequent small-scale clashes between Coptic Christians, who account for about 10% of Egyptians, and the Muslim majority but the shooting was the worst-known case of sectarian violence in a decade.
The United States Ambassador to Egypt is reported to have discussed the attack with the Coptic Pope Shenouda III when she visited him on Tuesday.
Two days later, a full two weeks after the incident, President Hosni Mubarak made his first remarks directly condemning what happened.
Copts say the tension between faiths had been building for some time
"The criminal act in Naga Hamady has made the hearts of Egyptians bleed, whether Copts or Muslims," he said in a speech carried on state-owned Nile News.
He called on "the rational preachers, thinkers and media men to shoulder their great responsibility in hampering sedition, ignorance and blind fanaticism and to deter hateful sectarian motives that threaten our social unity".
Yet several civil rights groups say it is the government and local officials who failed in their responsibility to anticipate the attack and ensure its aftermath was handled effectively.
The shooting in Naga Hamady has been linked to the alleged rape of a Muslim girl by a Coptic man in the nearby village of Farshut last November. Claims of the assault led to several days of unrest.
A report by the Egyptian Initiative for Personal Rights (EIPR), whose researchers went to the area on a fact-finding mission, states that local church authorities warned of possible violence and decided to end Christmas masses before midnight as a result.
It questions why police did not bolster security during the Coptic holiday or take further action to prevent angry clashes that followed the shooting when Muslims and Christians damaged each other's property.
EIPR found that dozens of local residents - from both faiths - were arrested at random. It alleges that some were tortured.
In February, three Muslim men are due to stand trial before an emergency security court charged with premeditated murder in Naga Hamady.
However EIPR director, Hossam Bahgat, believes there should be a wider inquiry into events.
Who are Egypts' Christians?
Egypt has the oldest and largest Christian community in the Middle East
About 10% of Egypt's 80 million people are Christians
Egyptian Christians are known as Copts, a word derived from the Greek word Aigyptos, meaning Egypt
The Christian community is divided into: Coptic Orthodox, Coptic Catholics, Coptic Evangelicans (Protestants) and other minorities
They have their own pope, Pope Shenouda III
"Since these killings on 6th January we have called on the public prosecutor to expand his investigation into the circumstances that led to them, the possible negligence by security agencies and people involved in inciting the violence," he says.
"We also believe this particular incident cannot be seen in isolation from the general picture in Egypt."
Analysts say there has been a rise in sectarian violence since the growth of Islamic movements in the 1970s.
It has led to an increasing number of Christians becoming radicalised, disgruntled at perceived discrimination. Widespread poverty exacerbates the situation.
Often, disputes over land and inter-faith relationships can spill over, splitting communities along religious lines.
There are warnings that the authorities must do more to deal with Christian grievances, including complaints about restrictions on building churches and a school curriculum focused on Islam.
"Nowadays everything is religious: the books in schools, the media. It's all adding to the divisions felt by the lower classes especially," reflects Amira, who also attends St Mary's Church.
"If the government did more to address the root causes of frustration it could make things better but I don't think that will happen. Instead when this hype dies down, things will probably go back to normal, until the next catastrophe."