The UN mission in South Sudan has apologized for failing to protect civilians during the attack at the base in Malakal last week.
At least 18 people were killed and about 80 others wounded in the attack.
UNMISS spokesperson Arianne Quentier says there were inadequate security personnel to maintain law and order at the protection site.
“We are really sorry, and sorry is an understatement,” Ms Quentier said during Eye Radio’s Dawn show. “It’s very sad that something like 18 people probably would not have lost their lives.”
However, Ms Ariane further said UNMISS and humanitarian groups are assessing the situation of the IDPs.