Cattle raids in a South Sudanese region near the border of Ethiopia have left at least 60 people injured and an unknown number dead, a UN mission said. The UN Mission in South Sudan said it sent troops and a medical team to Jonglei state following reports of cattle raid on a camp occupied by the Lou Nuer ethnic group. UNMISS said clashes between the Lou Nuer and Murle ethnic groups have been a security issue since December. Conflict in Jonglei claimed at least 1,000 lives in recent months. Conflict was triggered by cattle raids and high bridal dowries. Most of the victims are women and children. The tensions follow efforts to implement a voluntary disarmament campaign in Jonglei. Hilde Johnson, head of the UN peacekeeping mission for South Sudan, said UN personnel were following the process closely. \"UNMISS has a mandate to protect civilians. We will therefore monitor carefully what is happening,\" she told UN Radio. \"We will have a presence on the ground with our troops.\" South Sudan became an independent nation in July as part of a comprehensive peace deal that ended the Sudanese civil war. Oil disputes, ethnic conflicts and border clashes threaten the peace deal, however.