Police protected Islamist extremists who attacked a funeral service at St Mark's Cathedral in Cairo, according to a source close to Egypt's Catholic bishops.
Father Rafik Greiche, media representative for the country's Catholic Bishops' Conference, told Catholic charity Aid to the Church in Need that police had failed to protect Christians who were pelted with stones and molotov cocktails.
Pointing out that Islamist extremists had threatened to disrupt the service, he said: "The police must have been aware of the situation. So why were the police not in front of the cathedral?
"They only arrived two hours later, and then they protected the attackers."
According to reports, two people were killed and more than 90 injured when unknown attackers targeted mourners at St Mark's Coptic Orthodox Cathedral on Sunday 7th April.
The funerals of four Christians, who died during inter-religious clashes in Khusus, were transferred to the cathedral after fundamentalists threatened to attack the church in Khusus if the service was held there.
Speaking to Aid to the Church in Need, Coptic Catholic Bishop Kyrillos William Samaan of Assiut condemned the assault.
He said: "Nobody could have imagined that anybody would attack such an important symbol for all Egyptians as St Mark's Cathedral in Cairo.
"It is shocking. But we will never learn the real motives for these attacks."
A few hours after the attacks, Egypt's President Mohammed Morsi, who was formerly a member of the Muslim Brotherhood, expressed his solidarity in a telephone call to Coptic Orthodox Patriarch Tawadros II.
Fr Greiche stressed that moderate Muslims had expressed solidarity and sympathy towards the Christian community.
He said: "All of our Muslim friends told us that the events make them feel ashamed. I recently visited Azhar University, the most important Sunni institution.
"Sheiks with whom we are in contact there assured us that such attacks are not compatible with Islam."
Fr Greiche added: "We are in permanent contact with the Protestant and Orthodox Churches. We find much agreement. That is a blessing."
The priest noted improved relations with the Coptic Orthodox since Tawadros II was elected in November 2012 after the death of Shenouda III.
Fr Greiche said: "The atmosphere between Catholics and Orthodox Copts has been completely transformed. Tawadros is very open.
"For example he attended the enthronement of the new Coptic Catholic Patriarch Ibrahim Isaac. That had never happened before.
"But in particular, the Coptic Pope intends to visit the Pope in Rome. There has been a real change here."