Five aid workers have been killed in the line of duty since the beginning of this year

It has prompted the UN humanitarian co-ordinator in South Sudan, Sara Beysolow Nyanti, to call for joint action to address the humanitarian crisis and an immediate end to attacks against civilians and aid workers.

She made the call in the capital, Juba, on the eve of World Humanitarian Day, which is celebrated annually on 19 August.

Across South Sudan, aid workers and mostly nationals continue to be affected by armed violence, bureaucratic impediments and targeted violence, the UN says.

“It takes a village to raise a child. In the same way, it takes an array of partners to support crisis-affected people. We need urgent collective efforts to help the vulnerable population in South Sudan,” said Ms Nyanti.

She added: "All armed factions must immediately cease targeting civilians, humanitarian personnel and their assets. Impunity must end.”