French police were warned that one of the two Normandy hostage-takers was planning an attack but were unable to identify him.

France’s security services said they had received an alert from abroad and a photograph of an individual – later identified as Abdel Malik Nabil Petitjean – four days before Tuesday’s attack, but had no idea of his name or where and when he would strike. As a result, they were unable to link the information to the 19-year-old from Aix-les-Bains in the Savoie region of eastern France who was put on the Fiche S (S list) security register less than a month ago for attempting to travel to Syria.

The French intelligence services claimed the Turkish authorities, who picked up Petitjean on his way to Syria on 10 June, did not inform them of his arrest for 15 days. The security services put him on the S list on 29 June and alerted border authorities to arrest him when he re-entered France. He had slipped through the net, however, and already returned.

On Thursday, French police arrested a 20-year-old man also on the S list, who was reported to have been in contact with one of the Normandy attackers. “There is no evidence at this stage that he was aware of their plans,” a police spokesperson said.

About 10,000 people in France are on the S list, most of them alleged religious extremists, but officials say it is impossible to keep a close eye on each one.

A still from a video released via Isis showing the two attackers: Abed Kermiche, left, and Abdel Malik Nabil Petitjean.

On Thursday Petitjean was identified as the subject of the mysterious tipoff from abroad that a “person already on French soil” was planning an attack.

On Tuesday, Petitjean and Abed Kermiche, 19, took six people hostage at the church in Saint-Étienne-du-Rouvray near Rouen in Normandy, where they slit the throat of 85-year-old Father Jacques Hamel, and wounded a parishioner. The teenage attackers were shot by police as they left the church.

Petitjean’s identity card was found in Kermiche’s home. Telephone records suggest the pair only met recently, implying the attack was carried out on external orders.

Abdel Malik Nabil Petitjean’s identity card. Photograph: AFP/Getty Images

A video on a mobile phone, found during a search of another S list-suspect, showed a young man resembling Petitjean declaring his allegiance to Islamic State, but police were reportedly unable to identify him. It took a while after the Normandy attack for police to definitively link the attacker – who had been shot in the face by police – to the photograph sent from abroad and the identity card.

On Thursday evening, Isis’s official news agency, Amaq, released a video allegedly made by Petitjean before the Normandy attack, urging followers to carry out further terrorist attacks.

In the 2min, 27sec film, he warns the French president, François Hollande, and the prime minister, Manuel Valls: “The times have changed. You will suffer what our brothers and sisters are suffering. We are young and determined … we will destroy your country.”

There was no independent confirmation of the video.

Before Petitjean’s identity was confirmed by DNA tests, his mother, Yamina, refused to believe her son was involved. “No, no, no. It’s impossible. I know my son, he’s kind. I haven’t created a devil,” she told BFMTV. “He never talked about Islamic State ... We are positive people, we talk about good things ... He’s my baby.”



She insisted her son, who recently passed a CAP (professional aptitude certificate) in sales, was staying with a cousin in Nancy, but admitted neither she nor her 17-year-old daughter had heard from him since Monday evening. “Everyone around here knows my son. He’s a good boy. Calm,” she told RTL radio.

Three of Petitjean’s relatives were being questioned by police and the family home has been searched. Investigators insisted there was no evidence the three were in any way connected to the attack.

In Saint-Étienne-du-Rouvray, the prefect banned a silent march to honour Father Hamel for security reasons but allowed mourners to gather at the municipal stadium. Hamel’s funeral will take place on Tuesday at Rouen cathedral.

