The final words of Father Jacque Hamel, the French Catholic priest killed by Islamic State terrorists while saying morning mass, were recalled by a nun who witnessed his murder. Sisters Helene Decaux and Hugette Peron, both in their 80s, witnessed the horrific killing of Hamel in a Normandy church in Saint-Etienne-du-Rouvray, near Rouen.

Sister Helene described the moment when Adel Kermiche and Abdel Malik Petitjean, both 19, entered the church via a back door, with a knife and fake explosives. She said: "Jacques shouted at them, 'Stop! What are you doing?' It was then that one of them struck the first blow to his throat."

Fearing for her life, she added: "Thinking I was going to die, I offered my life to God."

The nun then described how Petitjean and Kermiche had at first been aggressive, but quietened down after they had cut Jacques' throat.

Showing remarkable calm, Helene asked the two terrorists if she could sit down.

"I asked for my cane, he gave it to me," she said.

One of the attackers asked: "Are you afraid to die?"

To which the nun replied no. "I believe in God, and I know I will be happy," Helene said.

Sister Huguette Peron, who was also in the church, told Catholic newspaper La Vie: "I got a smile from the second (man). Not a smile of triumph, but a soft smile, that of someone who is happy."

An 84-year-old parishioner was reportedly forced to video the terrifying scene by the terrorists, who then performed a "sermon in Arabic" at the church altar, according to witnesses.

Sister Danielle, who also present, said: "They told me 'you Christians, you kill us'. They forced him [Hamel] to his knees. He wanted to defend himself. And that's when the tragedy happened. They recorded themselves. They did a sort of sermon around the altar, in Arabic. It's a horror."

Petitjean and Kermiche were both shot dead by police marksmen outside the church on Tuesday, 26 July. In a video, they had pledged allegiance to the Islamic State terror group.

Petitjean, who used the nom de guerre Abu Omar, was on a terrorist watch list after attempting to travel to the Isis-controlled area of Syria via Turkey in June.