Both sides reported heavy fighting in the key oil-producing state of Upper Nile, which now pumps almost all of South Sudan's crude after intense battles shut down most fields in the other main area of Unity state. (Agencies)
Both army spokesman Philip Aguer and his rebel counterpart Lul Ruai Koang reported heavy artillery barrages and fierce gun battles at Dolieb Hill, south of Upper Nile's war-ravaged state capital Malakal, and in the northern Renk district.
"We will continue to strictly abide by the peace agreement, but we will not allow this ceasefire to be used by rebels to continue moving and attacking our positions," Aguer said.
Rebel spokesman Koang charged government troops today of "relentless and intensive shelling" of their positions at Dolieb.
He claimed government troops had fired shells as rebels gathered for a morning military parade to listen "to agreement messages being read out to them by their respective field commanders."
The war in the world's youngest nation has claimed thousands - possibly tens of thousands - of lives, with more than 1.2 million people forced to flee their homes.
In Renk district, a strategic region just north of the main oil-field still left pumping, Palouch, the rebels said government troops were "continuously attacking".
Aguer said it had been the guerrillas who had attacked.
President Salva Kiir and rebel chief Riek Machar signed a fresh ceasefire last week but fighting broke out hours later, the second time a truce has failed to stick.
The ceasefire agreement, signed last week in the Ethiopian capital Addis Ababa, was the fruit of weeks of mounting international pressure and shuttle diplomacy.
But fighters on the ground appear to have paid little if any notice to it.
United States on Wednesday called for an immediate deployment of African troops from regional nations to safeguard the ceasefire, with Washington seeking a UN resolution to ensure the force is in place "quickly as possible," said Linda Thomas-Greenfield, Assistant Secretary for African Affairs.
Thomas-Greenfield warned of possible dire consequences should the shaky peace deal fall apart.
"There is a famine that is looming if this fighting does not stop," she said.
Both sides reported heavy fighting in the key oil-producing state of Upper Nile, which now pumps almost all of South Sudan's crude after intense battles shut down most fields in the other main area of Unity state.