Intertribal violence may have left hundreds dead over the last week in South Sudan, according to the official in charge of the U.N. mission in that country .
Speaking by video link from Juba, Lise Grande, U.N. Deputy Humanitarian Coordinator for South Sudan, on Tuesday called the humanitarian situation in the region "grim," following an attack by members of the Lou Nuer ethnic group on the Murle tribe.
Grande could not confirm the death toll but estimated the number would be in the "tens, perhaps the hundreds."
The two tribes have traded violent attacks over the last several years that have killed thousands. Grande said the army had succeeded Tuesday in repelling the attacks with help from U.N. peacekeepers.