The convoy was stopped about ten or twenty miles downstream of Nasir by a force of Jikany Nuer tribesmen.[1][2] The tribesmen demanded to search the barges to check that arms and ammunition were not being shipped to their rivals in the Lou Nuer tribe.[1] They searched one barge, finding only food, but opened fire when the rest of the convoy tried to continue its journey.[1] The attack killed at least 40 Sudanese soldiers and wounded 30 others.[4] The deaths of several women and children by gunfire or drowning have also been reported.[1] The wounded were taken to a Médecins Sans Frontières hospital in Nasir which was braced to accept further casualties.[3] This was believed to be the first time the SPLA has suffered significant casualties in the recent tribal violence.[1]