"The Working Group reiterates its call for the immediate release of the detainees and the provision of reparations for the harm caused … We would like to remind Saudi Arabia of its obligations vis-à-vis these individuals, and we also recommend that it releases all those in similar situations," the group said in a statement, published on the website of the UN Office at Geneva.
The group added that it was necessary for Saudi Arabia to free other prisoners, jailed on the similar grounds, as the detention violates international standards on human rights.
According to the statement, almost all of the nine detainees were linked to the Saudi Civil and Political Rights Association (ACPRA), fighting for a reform related to the human rights issue until the government outlawed the group in 2013.
Besides, the UN group called on Saudi Arabia to ensure proper treatment of the prisoners and the absence of torture.
The UN body asked Riyadh to release the activists for the first time in 2015, according to the statement.