KABUL, Afghanistan — Women and girls in Afghan jails are frequently subjected to forced virginity tests, advocates from Afghanistan’s human rights commission said on Tuesday, calling for an end to a discredited practice that is both invasive and degrading.

A report by Afghanistan’s Independent Human Rights Commission, based on interviews with 53 female detainees across 12 of the country’s 34 provinces, found that 48 of them, including girls as young as 13, had been sent for virginity tests. The procedure, which has widely been found to be scientifically invalid, is frequently conducted in the presence of many people and in an invasive manner that could amount to rape or torture, the report said.

President Ashraf Ghani, who has not been briefed on the findings, was “deeply saddened” by reports of the practice, and had asked the human rights commission for a full review, said Sayed Zafar Hashemi, a spokesman for Mr. Ghani.

“The president expects the reformist chief justice to abolish the practice,” Mr. Hashemi said.

Around 750 women and girls are being held in jails and prisons across 29 provinces, according to Afghanistan’s Interior Ministry. Most of the women were detained on vague charges of “moral crimes” for running away from home — either with a lover other than the husband arranged for them by their families, or to escape domestic violence.