The arrests come less than a month before the Kingdom is scheduled to lift the ban on women driving, a reform announced a year ago under Crown Prince Mohammed Bin Salman's plan to expand liberalize aspects of Saudi's religious law, where women are treated as second-class citizens.
"The crown prince, who has styled himself as a reformer with Western allies and investors, should be thanking the activists for their contributions to the Saudi women's rights movement", she said.
"Amnesty International is anxious about reports of further arrests of individuals. and we call on the authorities to reveal the whereabouts of these individuals and reveal the charges against them", said Samah Hadid, Amnesty International's Middle East director of campaigns. They have been publicly branded traitors by pro-government media.
At 2:30pm on May 15, Hathloul's house was raided and she was arrested in her bedroom, according to Alqst, a Saudi human rights group based in London.
He is also seen as the architect of the three-year-long Saudi-led invasion of neighboring Yemen, which has killed and displaced tens of thousands, and a key proponent of maximum regional and global pressure on regional powerhouse Iran.
Prince Khaled's comments come amid the Saudi crown prince's mysterious absence from the public eye since heavy gunfire and explosions were reported just outside the royal palace in Riyadh late last month.
Activists told the AP that seven of those detained were involved in efforts to establish a non-governmental organization called "Amina" that would offer support and shelter to victims of domestic abuse.
Vedanta shares drop 6% after Sterlite protests in Tamil Nadu
Locals have alleged that the Sterlite copper plant is responsible for increasing pollution and have been demanding its closure. Reports also said they were seen armed with assault rifles and the deaths were attributed to police firing.
"Many people in the Kingdom have openly expressed their views on this issue and were not subject to any arrest or legal action, as they did not violate any of the regulations that are clearly enforced in Saudi Arabia", it added.
Other activists included, Madeha al-Ajroush, Aisha al-Mana, Hessah al-Sheikh.
Saudi Arabia's Crown Prince Mohammed bin Salman will cover all external debts owed by Saudi Professional League clubs, according to an announcement by The General Sports Authority and Saudi Arabia Football Federation (SAFF).
Saudi rights defenders said that in September 2017, the day the lifting of the ban was announced, officials working for the king's office (also known as al-Diwan al-Malaki in Arabic) had phoned prominent activists, including some of those now detained, and warned them not to speak to the media.
Women must adhere to a strict dress code, be separated from unrelated men, and be accompanied by or receive written permission from a male guardian - usually a father, husband or brother - if they want to travel, work or access healthcare. Both Nafjan and Yousef participated in a protest against the driving ban in 2013.
Saudi Arabia is set to lift its driving restriction on June 24.
In recent years, she has been cautious about voicing her opinion on Twitter out of concern over a growing crackdown on rights advocates. In his view, what is going on in the region right now is very unsafe. There are rights stipulated in Islam that they still don't have.
Such reforms have so far been limited. In addition to planning to lift the driving ban, the authorities have allowed women to hold jobs previously closed to them, such as air traffic control, border control, and traffic police. However, the male guardianship system, the most serious impediment to women's rights, remains largely intact.