Five people who are suspected of assisting the terrorist in Belgium who opened fire at the Brussels Jewish Museum this past spring were arrested on Tuesday in the southern French city of Marseille.

The five individuals – three men and two women, who are reportedly not related to each other – are suspected by authorities of helping Frenchman Mehdi Nemmouche to implement his attack, which resulted in the killing of four people in May.

On Friday, Nemmouche was remanded in custody for another three months, judicial officials disclosed.

The 29-year-old shooter, who is of Algerian origin and spent more than a year fighting alongside Islamic extremists in Syria, faces charges of “murder in a terrorist context” after he apparently carried out the fatal shooting of an Israeli couple, a French woman and a Belgian at the Jewish cultural institution in central Brussels.

As reported by i24news and AFP, the hearing was held in a closed session. Nemmouche was initially ordered held following his extradition from France at the end of July.

Nemmouche’s lawyers, who have not asked for bail, asserted at the last hearing that such an approach “was absolutely not an admission of guilt.” One of the lawyers, Sebastien Courtoy, had contended that there was a major problem with the prosecution, specifically that “there is no direct proof of the clear presence of Nemmouche at the scene.”

Courtoy claimed the authorities were attempting to publicly sully his client’s character by pointing to reports that Nemmouche had helped guard Western hostages being held by Islamic extremists in Syria.

The shooting at the Jewish Museum — the first attack of this type in Brussels in three decades — prompted worries of a resurgence of anti-Semitic violence in Europe, and more specifically of potential terrorist attacks by foreign fighters returning to European countries from Syria.

Nemmouche was arrested in Marseille after being sighted on a bus from Brussels. Authorities found in his luggage at that time a revolver and Kalashnikov rifle, which were quite similar to the weapons captured on museum security footage.