MSAKEN, Tunisia — The uncle of the truck driver who killed 84 people on the French Riviera says his nephew was indoctrinated about two weeks ago by an Algerian member of the Islamic State group in Nice.

French officials could not confirm Monday that attacker Mohamed Lahouaiyej Bouhlel had been approached by an Algerian recruiter, saying that the investigation is ongoing.

IS claimed responsibility for last week’s attack, though Interior Minister Bernard Cazeneuve said Monday that investigators have found no sign yet that Bouhlel had links to a particular network.