One of the two attackers who slit the throat of an elderly priest in a church in France has been named as Adel Kermiche.

The 18-year-old and his unnamed accomplice stormed the church in Saint-Etienne-du-Rouvray near Rouen in Normandy, France, and forced 86-year-old priest Jacques Hamel to kneel before slitting his throat on camera in the style of an Isis execution video.

One of the terrorists had a handgun and began to shout "Allah Akbar" and the other had a fake bomb with a timer. 

They then gave a "sermon in Arabic" at the altar and were shot dead by police. Their four other hostages, including two nuns and two parishioners, were then rescued after another nun managed to escape to raise the alarm.

Family friend Jonathan Sacarabany said Kermiche grew up in a housing project in Saint-Etienne-du-Rouvray.

Mr Sacarabany said the jihadist was originally born in Algeria and had a sister who is a doctor in Rouen and a brother. Their mother is a professor.

He said the family had previously told French authorities about his radicalisation to stop him going to Syria. He was arrested in 2015 while trying to get to Syria using his brother's passport and was sent back to France. 

In March this year he was arrested for plotting terrorist attacks.

Kermiche had been put under judicial supervision after his arrest but the electronic bracelet was deactivated for five hours a day allowing him to leave the house during the day without surveillance, an unnamed police official said.

The officer, who spoke on condition of anonymity, said Kermiche had been required to check in with police every day.

In a statement to the media, French prosecutor Francois Mollins said an investigation had been launched into the "cowardly" actions of the terrorists and a number of people had been arrested in connection with the attack.

He said they were still trying to identify the second attacker. 

It comes as French President Francois Hollande has cancelled a visit to the Czech Republic for the second time following another terror attack on the country.

He had planned to meet with Czech President Milos Zemand Prime Minister Bohuslav Sobotka to discuss the security situation in Europe. 

France and Germany had come under a wave of attacks in recent weeks with at least three Islamist terror incidents in Germany in the past weekand the events in Nice on 14 July where a lorry driver ploughed a car into the Bastille Day crowd killing 84 people.

Following the Nice attacks, Mr Hollande announced the extension of a state of emergency which had been in place since 130 people were killed in a string of shootings and bombings in Paris in November. 

Mr Hollande and Prime Minister Manuel Valls were booed at a memorial service for the victims of the attack after it was revealed the French government had denied a request by Christian Estrosi, the president of the region, for more security at the Bastille Day event.