A U.N. working group has concluded that North Korea’s imprisonment of three South Korean missionaries constitutes “arbitrary detention” without clear standards, demanding their immediate release after nearly 11 years, according to Seoul.

In a statement released Friday, South Korea’s unification ministry announced that the U.N. Working Group on Arbitrary Detention (WGAD), based in Geneva, adopted the stance on March 13 regarding missionaries Kim Jung-wook, Kim Kook-kie and Choi Chun-gil.

“The U.N. working group concluded that the deprivation of freedom of these missionaries by North Korea violates relevant provisions of the Universal Declaration of Human Rights and the International Covenant on