Wasu matasa sun harbe har lahira mutane 15 a yankin gabashin Pibor na kasar Sudan ta Kudu, ciki har da wani kwamishinan lardin, kamar yadda wani babban jami'i ya bayyana a ranar Laraba, a daidai lokacin da ake ci gaba da samun tashe-tashen hankula a yankin gabanin zaben kasar a karshen shekara