The medical humanitarian group Doctors Without Borders has accused the United Nations Mission in South Sudan of a “complete and utter failure” to protect civilians, according to The Guardian newspaper.

Civilians arriving at the protection-of-civilian site in Bentiu have told of widespread and uninhibited murder, rape and looting, according to Pete Buth, the deputy operations director of the group, which goes by the French acronym MSF.

“It’s not like this is a secret,” he told the newspaper. “They talk about the most horrendous incidents of sexual violence and I’m sure we’re only seeing the tip of the iceberg.”

An UNMISS spokesperson rejected the claims, pointing out that they protect civilians living in the POC site and conduct regular patrols into conflict areas of the state.