Armed gunmen on Friday robbed the compound of Nile Hope, a leading South Sudanese humanitarian organization, in the capital Juba.

The men held the Nile Hope staff at gunpoint and stole the organization's properties, according to a statement from the UN's Office for Coordination of Humanitarian Affairs (OCHA).

OCHA South Sudan chief Eugune Owusu strongly condemned the incident and demanded the perpetrators be brought to book.

"This is absolutely reprehensible and those responsible must be identified and held to account," Owusu said in a press statement. "I call on all relevant actors including the government to work together to strengthen our collective resolve to protect the safety and security of humanitarian workers."

OCHA said the staff of Nile Hope "work day in and day out" in difficult locations to help South Sudanese citizens in dire need, noting that violence and crime makes it harder for them to do their work.

There were 32 incidents of robbery, burglary, or looting of aid groups in October, including 15 incidents in Juba, OCHA said.