Staff at Rochester Cathedral are on high alert after the murder of a priest in France by an Islamic State-inspired extremist.

Police counter-terrorism experts visited the cathedral this week and new security measures are to be introduced, together with further guidance for staff and volunteers.

It comes after security was also tightened at Canterbury Cathedral and other churches across Kent in the wake of the Normandy attack.

A string of terror attacks across Europe has led British Intelligence officials to warn an attack on the UK is “very likely”, and the killing of a 86-year-old priest Jacques Hamel, at his church in Rouen on Tuesday, has brought church security into the spotlight.

His killer, Adel Kermiche, and another man, named as Abdel Malik P, were shot dead by police as they exited the Catholic church shouting “Allahu Akbar” – “God is great”.

The message from church officials is that church leaders and congregations should be “alert, not alarmed” in the wake of the attack.

“That’s the approach we’re taking – to be alert not alarmed,” said Rochester’s chapter clerk executive director Gilly Wilford. “That message was emailed round to all staff and volunteer welcomers.

“Our staff have all been informed to be extra vigilant and to look out for unlikely characters.

“We have a set of measures in place with a book of forms that staff complete if they see anyone at all unlikely.

“Obviously they would contact the police if anything untoward happened, but we use the book to make sure we have a record so we can establish if anyone’s making frequent visits.”

Mrs Wilford said further security measures were set to be introduced after Wednesday’s visit from the counter-terrorism unit, but did not want to compromise their effectiveness by providing further details.

Tightening security would not make the cathedral a less friendly place, she added.

“Rochester, unlike Canterbury, is free to enter and we want to continue to be welcoming to everybody,” said Mrs Wilford. “The fact that university graduations are happening here is a sign of that – the atmosphere yesterday was just lovely.

“But that took place in the context of excellent, well-organised security provided by the university and our in-house vergers.”