France, Oct. 19 -- The proceedings began on Monday in Aix-en-Provence under tight security, with 11 masked police officers positioned in the defendants' dock, while an armed security presence patrolled the streets around the courthouse.

Five men with alleged connections to a Marseille-based organised crime group, known as DZ Mafia, are on trial in connection with the killings of three men - Brahim Chabane, Reda Khaldi and Nassim Loubani.

Brahim Chabane is the older brother of Amine Kessaci - a 23-year-old anti-drug trafficking campaigner who has been under police protection for more than a year.

Kessaci, a city councillor in Marseille, arrived at court accompanied by masked police officers. Before entering, he said he was "seeking just...