Ten people were in police custody on Saturday, October 14, as part of the investigation into the Islamist attack in which a teacher was killed and three people were injured on Friday in Arras (Pas-de-Calais), according to a source policewoman.

Among those in police custody are several members of the attacker’s family: his sister, his mother, his uncle and two of his brothers, one of whom was taken from the cell where he is being held for “association with terrorist criminals.” Two Belarusians “with whom the attacker was during his police check the day before the incident” are also among those in custody, said another police source, “but there is nothing to say that they were involved” in the incident.

According to information from Le Monde, the attacker, Mohammed S., was the subject of active surveillance by the General Directorate of Internal Security (DGSI). He was checked on Thursday “without any charges being brought”, according to a police source. One of his brothers was arrested in 2019 at the age of 17, in Strasbourg, again according to information from Le Monde.

The latter was part of a cell of five radical Islamists, sympathizers of the terrorist organization Islamic State, who planned to kill police officers. On Friday, the National Anti-Terrorism Prosecutor’s Office (PNAT) opened an investigation into “assassination and attempted assassination in relation to a terrorist enterprise” and “terrorist criminal association”.

The attacker killed a teacher and injured two people, including one seriously, the day before at the Gambetta-Carnot high school. The man was arrested shortly after the incident by the police. Of Russian nationality, born in 2003 in Russia, he arrived in France in 2008, according to a source at the Ministry of the Interior. This is a former student of the establishment who is registered in the file for processing reports for the prevention of radicalization of a terrorist nature (FSPRT).