The resolution extends UNMISS's mandate for six months and changes its focus from promoting development and nation-building to protecting civilians and ending the violence in South Sudan.
Officials say government, rebels both deny responsibility for attack targeting four barges on the Nile River, carrying food and fuel to U.N. base in Malakal
Senior human rights official says 'thousands' of people have been killed in violence and some of worst human rights violations may constitute crimes against humanity
UN Security Council's president says about 14,000 civilians have taken shelter at a UN base that is now surrounded by up to 3,000 armed men
