The National Security Service has reportedly closed down the offices of the policy research firm, the Sudd Institute in Juba.
According to a senior researcher at the institute, some of its staff have been arrested and detained at the Blue House.
The Sudd Institute condemns the actions of the NSS and demands the release of those arrested.
Among those arrested is Dr Augustino Ting Mayai, the acting managing director of the institute.
In a Facebook post today, Dr. Jok Madut said the demand that the colleagues be charged and brought before a judge.
He criticized the government for what he calls resorting to arrests, intimidation, and arresting constitutionally protected rights of citizens.
The Sudd Institute is an independent research organization that conducts and facilitates research and training to improve the quality, impact, and accountability of local, national, and international policy and decision-making in South Sudan.