At least 25 people have been killed in South Sudan, officials said, after youths from two neighbouring communities in the country’s north clashed over a disputed borderline separating their areas. Violence is endemic in parts of South Sudan where clashes triggered by localised disputes over grazing areas, water, cultivation grounds and other resources often turn deadly. The country’s volatile politics often helps exacerbate some of the localised disputes, fanning the violence. In the latest unrest, armed youths from the Twic community in Warrap state on the border with Sudan on Monday attacked…