Der gik ikke mange timer, før parterne i den blodige borgerkrigsagtige konflikt i Afrikas nyeste nation beskyldte hinanden for at bryde en våbenhvileaftale, indgået fredag, men der er lagt stort internationalt pres på de to stridende hovedkombattanter.
The army said rebels attacked government positions in the early hours of Sunday in the town of Bentiu in oil-rich Unity State, BBC online reports Sunday.
The rebels said their positions were targeted by ground attack and artillery in Unity and Upper Nile states.
A deal to end the five-month conflict was signed on Friday in Ethiopia.
At the signing ceremony in Addis Ababa, President Salva Kiir and rebel leader Riek Machar met face-to-face for the first time since hostilities broke out and agreed to halt fighting within 24 hours.
A previous deal, made in January, collapsed in days, with each side accusing the other of breaching terms.
Earlier, the UN called on both sides to facilitate deliveries of emergency aid to a population in danger of mass hunger.
The UN estimates that some five million of South Sudan’s citizens are in need. At least 1.5 million have been displaced and thousands of people have been killed.
The hope had been that the ceasefire would pave the way for the creation of a transitional government, the drafting of a new constitution and fresh elections.
The UN has accused both the South Sudanese government and the rebels of crimes against humanity, including mass killings and gang-rape.
