A senior Church leader in the UK has warned the murder of a priest in Normandy could be a "sign of things to come".

A priest was killed on Tuesday morning by two assailants as he celebrated mass in a church in Saint-Etienne-du-Rouvray, near Rouen in northern France. Five people in the congregation were taken hostage and one was seriously wounded and left fighting for their life. The two hostage takers were shot dead by the French police.

But the Church leader, who wished to remain anonymous for fear of reprisals, told Christian Today a trend of attacks on Christians was developing and he was worried more would follow.

"There needs to be a connection made between what is happening here and what has been happening in places such as Egypt, Nigeria, Pakistan and Iraq," the source told Christian Today.

"Suddenly we are seeing this in Europe. It could be an alarming sign of things to come.

"There is a lot of copycat psychology in these kinds of attacks. We are hoping this does not turn into anything more serious and get out of hand, but we are concerned that it might."

Earlier this week the head of the Coptic Church in the UK, Bishop Angaelos, described the "exponential rise in attacks against Christians and Christian property" in Egypt. He warned that if they were not addressed, the attacks would "spiral even further". 

He told Christian Today on Tuesday that "unfortunately these attacks seem to have reached Europe". In Egypt terrorists began by targeting secular sites and areas such as markets before moving on to churches and religious buildings. 

Angaelos warned that if attacks on Christians in Europe followed a similiar pattern to Egypt it would make "every church and every pastor of whatever denomination a possible target". He told Christian Today a "pattern was emerging" where innocent people were killed. 

"We've seen similiar attacks in places of celebration and of worship," he said. "When people go to places of worship they are probably at their most vulnerable."

Pope Francis condemned the "absurd violence" and "all forms of hatred", according to his spokesman Father Federico Lombardi. He said the pontiff, who is also in Poland for World Youth Day, was "horrified and shocked" by the attack.

"We are particularly shocked because this horrible violence took place in a church, in which God's love is announced, with the barbarous killing of a priest and the involvement of the faithful," he added.

The Archbishop of Canterbury, Justin Welby, called for prayer in a tweet after the attack.

The Archbishop of Rouen, whose diocese covers the parish of Saint-Etienne-du-Rouvray, will return from Poland where he had been participating in the World Youth Day celebrations. He said the Church "cannot take weapons other than those of prayer and brotherhood among men". He added the whole parish was "very much in shock".

He urged Christians "not to give in to the violence and become apostles of the civilization of love".

Mohammed Safiq, chief executive of the Ramadan Foundation, described the attack as a "brutal murder" and "condemned [it] in the strongest terms".

He said Europe faced daily threats from both ISIS and from far-right extremism.

"They are two cheeks of the same backside," he said. "They want divided communities and we must not allow them to succeed.

"Places of worship are sacred and in Islam it is forbidden to see such attacks and the brutal killing of a priest. An attack as we saw today in Normandy is an attack against all faiths and we stand together in solidarity, love and unity."