A number of prominent activists have reportedly been detained in Saudi Arabia.
Social media users suggested that at least five people, including high-profile women’s rights campaigners, were arrested on Thursday, the first night of the holy month of Ramadan.
The news comes just over a month before the conservative kingdom lifts its decades-long ban on women driving.
The Saudi government has not commented on the arrests.
But one activist told Reuters on condition of anonymity that authorities had arrested the activists “because they do not want them to publicly claim success” when the driving ban is lifted on 24 June.
Rights groups had campaigned for years for women to be given the right to drive, with some facing arrest when they broke the law.
Saudi Arabia lifted the ban in September last year.
It is one of a number of recent reforms in the country credited to 32-year-old Crown Prince Mohammed bin Salman, who has spearheaded the Vision 2030 programme to diversify the economy away from oil and open up society.
But the changes have not been uneventful. In November last year, dozens of high-profile princes, businessmen and former and serving ministers were rounded up in an anti-corruption drive seen by many as a purge by the crown prince.