JUBA( Reuters)-Young men shot dead 15 people in South Sudan's eastern Pibor region, including a county commissioner, a senior official said on Wednesday, amid a rise in local conflict ahead of a national election due at the end of the year.... Some activists say they believe a recent rise in killings is at least partly connected to the vote, which will choose leaders to succeed the current transitional government.... " The commissioner with his team went to Nyat village and on his return he wa