Female detainees appear to have suffered special abuse, according to two people familiar with several cases and reports this week from two rights groups, Human Rights Watch and Amnesty International. Two people familiar with the cases said this week that some women’s rights activists had been subjected to electrical shocks, whipping and verbal and sexual harassment.

A Saudi official who spoke only on the condition of anonymity said the kingdom “does not condone, promote or allow the use of torture,” whether “physical, sexual or psychological.”

The activists had risen to prominence for calling for the end of Saudi Arabia’s longstanding ban on women driving. Prince Mohammed lifted the ban this summer, but his government also arrested many of those who had called for the change, evidently to prevent them from taking credit or demanding more.

The Saudi government has not identified the detainees, saying only that a number were under investigation for vague charges of conspiring with hostile forces against the kingdom. ”

In interviews with The New York Times, two people familiar with the activists’ cases said some had arrived at meetings with their families trembling or with red marks on their faces, necks and limbs. Some had been deprived of sleep, the people said, speaking on the condition of anonymity for fear of retribution.