Six months after their abductions, Mountaga Tall, an outspoken critic of Mali ’s junta, and his son, Cheick Mamadou Tall, remain missing, their fate unknown, and the Malian authorities silent. Every day that passes without news raises fears for their safety and deepens their family’s anguish.

Unidentified gunmen abducted Tall in Bamako, Mali’s capital, on May 2. Tall’s son went missing on May 16 after receiving a call informing him that he could deliver belongings to his father, who was reportedly being held at an undisclosed location.

Radio France Internationale reported in July that the United Nations Committee on Enforced Disappearances had urged Mali’s authorities to locate and protect Tall and his son.

International media suggest that Malian intelligence services may be holding Tall in a secret facility.…