The U.N. Security Council has condemned fighting in two northern states in South Sudan and the repeated violations of a cease-fire agreement the government and rebels signed early last year.
In a statement late Sunday, the council said a government military offensive in Unity State caused large-scale violence that has forced 100,000 people from their homes and halted aid delivery to civilians in the area.
The council also blamed the rebels for launching an attack on the town of Malakal in Upper Nile state.
A bloc of East African nations that has been trying to mediate the conflict between President Salva Kiir's government and rebels backing former Vice President Riek Machar said it was "deeply frustrated" by the rebel violence in Malakal.
The Intergovernmental Authority on Development urged both sides to follow through on their agreement and find a peaceful end to the crisis.