South Sudan's government said 15 young children have died in a botched measles vaccination campaign which saw people as young as 12 years old administering the vaccines.
The health ministry on Friday blamed the deaths on human error. One syringe was used for all the children, and the vaccine was not stored properly.
The government said all of the children who died were under the age of five. It is setting up a commission to determine who is responsible and whether victims' families will be compensated.
The measles vaccination campaign is targeting more than two million children across the country.
The World Health Organisation provides some training to South Sudan's health officials and the UN children's agency provides the vaccines to the government.