BRUSSELS (AFP) - A Frenchman suspected in the shooting deaths of four people at the Jewish Museum in Brussels was remanded in custody for a month Monday on charges of "murder in a terrorist context".

Mehdi Nemmouche, 29, who spent more than a year fighting with Islamic extremists in Syria, was extradited from France to Belgium last week for questioning over the May 24 shooting.

A statement from the Belgian prosecutor's office said the Brussels pre-trial chamber "has ordered further detention on remand of NM by one month."

One of his lawyers, Sebastien Courtoy, said there was no proof of his presence that day at the museum, so "it is totally premature to condemn him at this stage".

The Frenchman of Algerian descent is being questioned over the deaths of an Israeli couple, a Frenchwoman and a Belgian man by a gunman who opened fire at the downtown museum in broad daylight on a Saturday afternoon.

The shooting - the first such attack in Brussels in three decades - raised fears of a resurgence of anti-Semitic violence in Europe and of terror attacks from foreign fighters returning from Syria.

Nemmouche was arrested in the southern French city of Marseille days after the attack after being spotted on a bus from Brussels.

A revolver and Kalashnikov rifle were found in his luggage, resembling weapons caught on a museum video camera, as was a camera.

Nemmouche, who is being held in prison in the city of Bruges, is being defended by two lawyers who have been photographed with controversial French comic Dieudonne, attacked for sketches deemed anti-Semitic.

A photo shows Courtoy and Henry Larquay along with Dieudonne making his trademark "quenelle" salute - a stiff-arm gesture described by critics as a disguised Nazi salute.

Nemmouche has been sentenced seven times in France, including for armed robbery, and has spent seven years in jail where he was notably found proselytising Islam.