The SPLA-Juba now requires all aid groups to declare their cargo when attaining clearance for humanitarian flights in South Sudan.

"When you are applying for flight clearance assurance, you are requested to attach the waybill and the detail of all the items that you're carrying to the field," reads a letter seen by Radio Tamazuj sent to NGOs last month by Brigadier General Majier Deng Kur, the SPLA-Juba's Joint Verification and Monitoring Mechanism Senior Team Leader.

One humanitarian official said the order was an "impossible" demand that amounts to bureaucratic harassment.

"For NGOs this is very difficult to plan ahead of time exactly what is going on a certain flight, so it creates an unrealistic rule that will be difficult [or] impossible to meet," the official said.

In January, SPLA-Juba chairman Salva Kiir and SPLA-IO chairman Riek Machar agreed to allow unrestricted humanitarian access to civilians in need. Both men have recommitted to that agreement at least three times since.

This article is part of an exclusive Radio Tamazuj series documenting harassment and violence against aid workers in South Sudan. If you have information on harassment of humanitarians or restrictions on aid, please contact Radio Tamazuj here.