PARIS (AP) — A French judicial official says five people have been arrested and detained in relation with the investigation into the Christmas market attack that left five dead in Strasbourg in December.

The judicial official, who is not authorized to speak publicly about the investigation, says they were arrested on Tuesday. He did not confirm reports in French media that they are suspected of helping the gunman getting his weapon.

The alleged killer, Cherif Chekatt, had pledged allegiance to the Islamic State group. He died in a shootout with police two days after the Dec. 11 attack at Strasbourg's popular Christmas market.