The UN slammed Monday a deadly attack over the weekend on aid trucks delivering assistance in southern South Sudan, prompting a suspension of aid deliveries in the area, Paralel.Az reports citing AFP.

Two aid trucks were attacked Saturday morning while returning to Juba after delivering aid for children and their families in Yei, in Central Equatoria State, the United Nations aid agency OCHA said in a statement.

OCHA said it “strongly condemned (the) deadly attack,” in which “two drivers were shot and killed, and both trucks were burnt and destroyed.”

As a result, the UN children’s agency UNICEF “has paused moving supplies to the area,” it said.

The UN’s acting humanitarian coordinator in the country, Mary-Ellen McGroarty had insisted on the importance of ensuring that those who provide vital assistance to the most vulnerable are protected.

“The killing of those who deliver support to save lives is unacceptable,” the statement said.

The UN warned that such violent incidents threaten the safe delivery of aid across South Sudan, which ranks as the deadliest place in the world for humanitarians.

So far this year, 24 aid workers have been killed in the country, the UN said.