The head of the Coptic Orthodox Church in the UK has announced three days of prayer for Egypt.
Bishop Angaelos said it was unfortunate that peaceful demonstrations for a new Egypt have been "undermined by needless violence and bloodshed".
Egyptians have been promised new elections by next February as the interim leadership seeks to bring the situation under control.
On Monday, more than 50 supporters of ousted President Mohamed Morsi were killed by security forces in Cairo. The Muslim Brotherhood has called the incident a massacre.
Coptic Christians in the UK are dedicating the next three days to prayer for peace, reconciliation and an end to violence and the loss of life in Egypt. They are inviting Egyptians of all faiths to join them in praying.
"For the good of Egypt, it is imperative that all parties work towards a common future, realising that any lives taken are those of fellow Egyptians," said Bishop Angaelos.
"We continue to pray for unity and reconciliation, confident that the spirit that has been developing over the past two years and culminated in June 30, 2013, will endure over these vital weeks and months ahead."
Bishop Angaelos is due this morning to address the Church of England General Synod on the situation in Egypt.
Speaking to reporters on Monday, the Archbishop of Canterbury the Most Reverend Justin Welby said there had been a "profound sense of foreboding" among the Christian and Muslim leaders he met in Egypt during a visit to the country at the end of June.
"We just hope and pray that it doesn't degenerate," he said.