The chief suspect in a deadly attack on a Paris synagogue in 1980 has been released on bail after being held for 18 months, judicial and investigation sources told AFP Tuesday.

Hassan Diab, 62, is accused of being part of the Special Operations branch of the Popular Front for the Liberation of Palestine (PFLP). The PFLP was blamed for the bombing on October 3, 1980, that left four dead and around 40 injured.

Diab was released on bail on Saturday after a judge ruled there was a doubt on the "fundamental question" of whether he was in France on the day of the attack.