The police in Riyadh, the Saudi capital, turned her over to the public prosecutor’s office, the kingdom’s state-run Alekhbariya television reported on its Twitter feed, using an Arabic hashtag that translates to “We demand a trial for the model Khulood.”

In the short clip, filmed mostly from behind, the woman is shown walking through the ruins of an ancient fort in Ushaiager, a town in Najd Province. Najd is the birthplace of the country’s ultraconservative Wahhabi religious movement.

In response to calls for the woman’s arrest, the Committee for the Promotion of Virtue and the Prevention of Vice wrote on Twitter on Monday that it had “intercepted a clip of a girl in inappropriate clothing” and had opened an investigation with the “relevant authorities.”

Saudi law imposes stringent rules on women’s appearance and behavior. Saudi women are required to wear a black garment, called an abaya, that covers everything but the face, feet and hands. They must also keep their heads covered, and they are not permitted to drive or to socialize with men who are not related to them.

An unidentified spokesman for the Riyadh police cited by the Saudi online news site Sabq said the woman had told the police that she visited the site in Ushaiager with her legal guardian — a male relative, usually a father or husband, but sometimes a brother or son, who has the legal authority to control a woman’s movements — and that the video had been put online without her knowledge.