The Human Rights Watch has added its appeal to the calls to release or try political activist Peter Biar Ajak.
Mr Ajak is nearly two weeks at the national security dentation facility known as the ‘Blue house’ without any charges.
He was caught by security personnel while waiting to board a flight to Aweil to attend the 8th Martyrs’ Day celebrations organized by the Red Army.
The motive of the arrest is unclear, but the activist has been critical of the government.
“South Sudanese authorities should release Mr Ajak and everyone else being held arbitrarily in detention,” Jehanne Henry, the rights monitor associate Africa director stated.
“Ajak’s detention is part of a deeply troubling pattern of increasing government repression against its critics since December 2013,” Mrs Jehanne added.
She called on the national security should change the way they operate and they should be subject to oversight monitoring and held accountable for their abuses.
After the signing of Khartoum agreement, President Kiir called on the security organs to stop any arbitrary arrest of dissidents in the country.