Twenty survivors of Saddam Hussein’s deadly 1988 chemical weapons attack on the Kurdish town of Halabja have requested a judicial investigation of French suppliers, saying executives knew what they were sending to the Iraqi dictator.

Saddam ordered the poison gas strikes to crush a Kurdish rebellion, which was seen as aiding Iran in the final months of its war with Iraq; 5,000 people died.

Gavriel Mairone, a lawyer for the group that filed the complaint in France, said those who survived continue to suffer health problems and are demanding the weapons’ suppliers take responsibility.