Thousands attend service in Rouen cathedral for Father Jacques Hamel, who was killed while celebrating mass last week

Exactly a week after two terrorists killed Father Jacques Hamel while he said mass in his own church, nearly 2,000 mourners paid their respects to the Catholic priest, described by his sister as “my brother. Everyone’s brother.”

The emotionally powerful ceremony at Rouen cathedral, attended by the French interior minister, Bernard Cazeneuve, and religious leaders including Muslim representatives, took place amid high security.

Hundreds of people who could not get into the cathedral watched the ceremony from under umbrellas on a big screen.

Facebook Twitter Pinterest Priests lead the procession as Father Hamel’s coffin is carried to the cathedral. Photograph: Jacky Naegelen/Reuters

Dominique Lebrun, the archbishop of Rouen, told mourners that after his throat was slit, Hamel pushed one of his attackers with his feet, saying: “Get away, Satan.” Praising the murdered clergyman for 58 years of loyal service to the church, he said: “Jacques, you were a loyal disciple of Jesus. Where you went you did good.”

Saluting representatives of the Muslim and Jewish faiths, he called for peace and tolerance adding: “Never again.” It was not a question of forgiving those who had made a “pact with the devil”, but called on those taken by “demonic madness” to remember their mothers “who gave you life”.

Roselyne Hamel, the priest’s elder sister, told the congregation her brother had served in the Franco-Algerian war but had refused an officer’s commission because he would not “order men to kill other men”.

In a tearful tribute, Hamel’s niece, Jessica Delporte, added: “After Charlie Hebdo I posted this phrase [on social media] ‘Oh my God, let’s keep our tolerance and discernment’, never thinking I would have to apply that phrase to myself with so much force and conviction.”

Hamel, 85, was among six people taken hostage when two men who had pledged allegiance to Islamic State stormed the church at Saint-Étienne-du-Rouvray.

The attackers, Adel Kermiche and Abdel Malik Petitjean, both 19, forced the priest to kneel before slitting his throat, then stabbed one of his elderly parishioners. Sister Danielle, one of three nuns present, managed to escape and raise the alarm. The attackers were shot dead as they left the church.

Facebook Twitter Pinterest People watch the service from outside the cathedral. Photograph: Jacky Naegelen/Reuters

Kermiche and Petitjean, who are thought to have met for the first time only days before the attack after making contact on the encrypted messaging app Telegram, had both tried to join Isis in Syria. Kermiche had been released from prison, where he had been awaiting trial for two attempts to join the jihadis, and was wearing an electronic tag at the time of the attack.

Saint-Étienne-du-Rouvray’s Muslims have opposed suggestions that Kermiche could be buried in the town where he killed the local priest.

“Given that he’s a terrorist who has done us much wrong, he doesn’t deserve any respect,” Mohammed Karabila, imam of the mosque at Saint-Étienne-du-Rouvray, told Europe 1 radio. “Having said that, his remains have to be buried somewhere. There will be no official [mosque] representative and no prayer at the mosque.” The town authorities at Saint-Étienne-du-Rouvray have not decided whether to allow the terrorist’s burial in their district.

Facebook Twitter Pinterest Police officers watch Muslim worshippers leaving the funeral mass. Photograph: Michel Euler/AP

Three men are in the custody of anti-terrorist police and are being questioned about their connection to the attack. One of them, a 30-year-old cousin of Petitjean, is accused of “association with criminals in relation to an illegal terrorist organisation”. The public prosecutor’s office said the suspect “was perfectly aware that his cousin’s violent plan of action was imminent”, adding that examination of the man’s phone and computer revealed that he knew “a lot more than he wanted to tell police”.

A 17-year-old who tried to reach Syria with Kermiche in 2015 before he was arrested in Switzerland and a 19-year-old are also under arrest.

On Monday evening, Brittany Ferries carried out an exercise with a view to introducing armed sea marshals on board French cross-Channel vessels. No firm plan has been announced to make trained military personnel part of the crew.