A French extremist appeared in court Monday (January 7th) ahead of his trial for killing four people at a Jewish museum in Brussels in 2014 following his return from Syria, AFP reported.

Mehdi Nemmouche faces a life sentence if convicted over the killing spree in the Belgian capital on May 24th, 2014, which killed two tourists, a volunteer and a receptionist at the museum.

The criminal court in Brussels on Monday selected the 12-member jury ahead of the start of the full trial on Thursday.

More than 100 witnesses are due to testify at the trial, which will be attended by the victims' families and Jewish community leaders and could last until the end of February.

Nemmouche was arrested six days after the attack in the French port city of Marseille.

Before the attack, he is said to have fought in Syria as part of an extremist faction, and is also accused of acting as a jailer of kidnapped French journalists.

Investigators say he was in Syria from 2013 to 2014, where he met Najim Laachraoui, a member of the gang which went on to carry out suicide bombings in Brussels that killed 32 people in March 2016.

That same Brussels cell is also alleged to have co-ordinated and sent extremists to carry out the Paris massacre of November 13, 2015, in which 130 people were killed and hundreds wounded.

Both attacks were claimed by the "Islamic State of Iraq and Syria" (ISIS).