SINTET, Gambia — Matty Sanyang was at a baby naming ceremony when the soldiers arrived in Sintet, a farming town not far from the West African coast, pulled her neighbors from their homes and announced that the president had made a decision: The people of her village were witches, and they would need to be cured.

Then, she said, the soldiers pushed her into a truck, stripped her naked and forced her to say she was a witch.

“What they took,” said Ms. Sanyang, “was our dignity.”

On Monday, a public national truth and reconciliation commission in Gambia began hearing testimony from citizens like Ms. Sanyang who say they were victims of what commission officials are calling “witch hunts” ordered by Yahya Jammeh, the former president who ruled for 22 years before fleeing abroad in 2017 with his fleet of luxury cars.

The commission is designed to investigate atrocities perpetrated during his long reign. As president, Mr. Jammeh jailed dissidents, ordered extrajudicial killings and forced AIDS patients to quit their medications and submit to an herbal regimen of his own invention, according to human rights advocates.