South Sudan's warring factions have clashed in Upper Nile, Jonglei and Unity States, just days after their leaders agreed to unconditionally end fighting.
A rebel spokesman blamed the government for attacking their positions, including oil fields; while the army accused the rebels of restarting the conflict, saying their attacks were repelled.
President Salva Kiir has been embroiled in a power struggle with his fired deputy, Riek Machar, whom he accused of trying to oust him through a coup last December.
Riek Machar (left) and Salva Kiir (right)
Since the attempted coup, militia loyal to both have battled each others' forces resulting in violence and mass killings nationwide. The conflict is divided along tribal lines - the Nuer community backs rebel leader Machar while the President is a Dinka.
Previous ceasefire deals signed by the two sides have collapsed.
Kiir and Machar held two days of talks in Addis Ababa last week in a mediation effort brokered by the Inter-Governmental Authority on Development (IGAD), which groups eight East African countries. Kiir and Machar agreed to an "unconditional, complete and immediate end to all hostilities."
IGAD gave both sides a 15-day deadline to end conflict or risk sanctions including travel bans and an arms embargo.
Following the conclusion of the 28 Extra-Ordinary Summit of the IGAD Assembly of Heads of State and Government, the IGAD Special Envoys for South Sudan welcomed the agreement today by the Government of the Republic of South Sudan and the SPLM/A (In Opposition) of the implementation matrix and a detailed timetable to implement the Cessation of Hostilities Agreement in South Sudan.
IGAD noted that "Agreement of the timetable is a vital step to bring the war in South Sudan to an end. The IGAD Special Envoys call on the parties to swiftly and earnestly take all measures to implement the agreed timetable, without delay."
According to the United Nations (UN), the conflict has displaced some 1.5 million people and more than seven million are at risk of hunger and disease. The conflict has also severely disrupted the country's oil production. There are fears that the conflict may spill into neighbouring nations already taking in refugees fleeing the violence.
South Sudan seceded from Sudan in 2011 after decades of war, making it the world's youngest nation.