The World Food Program (WFP) has suspended operations in parts of northern South Sudan after armed youths attacked and looted a river convoy carrying more than 1,500 tonnes of humanitarian aid, the agency said on Wednesday.

The attack took place last week in Upper Nile State, where a 12-boat convoy transporting food and other relief items was assaulted multiple times and stripped of its cargo overnight, despite prior security assurances from local authorities.

WFP said that it would halt all activities in Baliet County until the safety of its staff and partners is guaranteed and the stolen supplies are recovered.

The incident comes amid escalating violence linked to political tensions between supporters of President Salva Kiir and his longtime rival, Riek Machar, particularly in Jonglei State, where the United Nations reports that at least 280,000 people have been displaced in recent weeks.

Local officials said security forces attempted to protect the convoy but were overwhelmed by armed attackers. 

Humanitarian agencies have warned that continued insecurity and access restrictions are severely hampering aid delivery in a country already struggling with conflict, poverty, and chronic instability since gaining independence in 2011.