A Saudi women's group on Friday blamed the country's religious police in the "honour" killing of two sisters shot dead by their own brother after they were arrested for mixing with unrelated men.
The Society for Defending Women's Rights in Saudi Arabia said the religious police had placed the sisters' lives in danger when they arrested them and then placed them in a Riyadh women's shelter.
The two women, identified as Reem, 21, and Nouf, 19, were murdered after they left the shelter on July 5.
The brother shot them in the presence of their father who, according to newspaper reports, quickly forgave the son for defending the family's honour.
But the society blamed the Commission for the Promotion of Virtue and Prevention of Vice, or the religious police, for sparking the brother's anger over his family's honour by arresting the girls in the first place.
"The hands of the religious police, as well as the brother's hands, are stained with the blood of these innocent young women," the group said in a statement.
"These women have not committed any crime to be killed in a such brutal way."
Under Saudi Arabia's Islamic sharia legal code, unrelated men and women are not allowed to mix together, and the religious police actively enforce the rules by patrolling areas frequented by young people.
"Arresting women for mingling with (unrelated males) should be stopped because it puts many Saudi women in danger and sometimes (costs) them their lives," the statement said.
"This act has nothing to do with the religion of Islam or Saudi tradition."
The women's group called on the Saudi authorities to charge the brother with murder and also bring to justice members of the religious police involved in the two girls' case.