International rights groups have condemned the arrests of at least seven prominent Saudi Arabian women's rights activists who previously campaigned for women's right to drive, which the conservative kingdom is set to grant from next month.
The bold reforms have been accompanied by a crackdown on dissent.
A government statement says the arrests are for suspicious contacts with foreign entities and offering financial support to enemies overseas.
Women will be allowed to drive starting on June 24.
However activists and analysts say the government is keen to avoid rewarding activism, which is forbidden in the absolute monarchy.
And may also aim to avoid antagonizing the sensitivities of religious conservatives opposed to modernization.
Human Rights Watch say the only crime it appears the detained women committed was wanting to drive before the powerful crown Prince said it was OK.