JUBA: South Sudan rebels and government troops battled Monday over the strategic town of Nasir, the United Nations said, with rebels launching their largest offensive since an oft-broken May truce.
Heavy shooting continued for a second day with fighting continuing in the northern town and rebel forces apparently in "firm control" of the center, U.N. spokesman Joe Contreras said.
The United Nations warned Sunday that the fresh rebel offensive "represents the most serious resumption of hostilities" since President Salva Kiir and his former deputy, rebel leader Riek Machar, met in May promising again to stick to a January cease-fire.
More than seven months of war has left thousands dead and displaced 1.5 million people, and aid agencies are warning of famine if fighting continues.
UNMISS, the U.N. mission, laid the blame for the truce violation squarely with Machar's forces.
The rebels claim to control the town, their former headquarters, located some 500 kilometers north of Juba and close to the Ethiopian border.
But the United Nations said that fighting was going on, with the heaviest clashes Monday reported around the government army barracks, just west of the town.
U.N. peacekeepers remain in control of their base, where more than two dozen civilians are sheltering inside.
Fighting in South Sudan had eased since May, in part due to heavy rains that have hampered troop movements.
Previous cease-fire deals have failed to stick, and peace talks in luxury hotels in the Ethiopian capital Addis Ababa have made little progress.
Last month they halted indefinitely, with both sides refusing to attend the discussions, and blaming each other for the failure.
Earlier this month the departing U.N. representative in South Sudan Hilde Johnson issued a scathing attack on country's leaders, lashing out at both the government and rebels, calling them a "self-serving elite" responsible for a looming "man-made famine."
Civilians have been massacred and dumped in mass graves, patients murdered in hospitals and churches, and entire towns flattened as urban centers, including key oil-producing hubs, changed hands several times.