South Sudan accuses rebels of breaking ceasefire: minister

South Sudan?s government accused rebel forces of breaking a ceasefire Saturday, less than 24 hours after it began and dashing hopes of a swift end to the brutal conflict.

"This morning I am informed that the rebel forces are still continuing attacking our forces," Minister of Information Michael Makuei said, speaking to reporters as he arrived back from the talks in Ethiopia that hammered out the crucial deal.

"Our forces... will have to defend themselves," he added.

But Makuei also insisted the government remained committed to trying to make the deal work, calling on the regional nations who helped broker the agreement to ensure it was now enforced.

The ceasefire, aimed to bring an end to five weeks of bitter conflict in which thousands have died, formally began at 1730 GMT on Friday.

Both sides have pledged to stick to a deal, but have also said they doubt the other can fully control the forces on the ground.

"This is not strange, these are rebels and... rebels are indisciplined people, they have no regular forces, no central command," Makuei said, but adding he believed the deal could still work.

"It was not a wasted time," he added, speaking of the negotiation efforts. "We will try our level best to ensure that the cessation of hostilities is properly monitored."

He did not give any details of the scale of fighting, or where the reported clashes had taken place.

It was not possible Saturday to immediately contact rebel forces.

The world's newest nation has been at war since December 15, with thousands killed and close to half a million forced to flee their homes.

Some have sought refuge in UN bases from the ethnic violence, other to large, squalid camps while tens of thousands of others have fled to neighbouring countries.

Up to 10,000 people are believed to have been killed in the fighting pitting forces loyal to Kiir against a loose coalition of army defectors and ethnic militia nominally headed by Machar, a seasoned guerrilla fighter.

The fighting has been marked by atrocities on both sides with some 700,000 people forced from their homes in the impoverished nation, according to the United Nations.

Refugees from South Sudan fetch water at the Dzaipi Refugee Transit Centre in Adjumani, Uganda, on January 24, 2014

A picture from January 24, 2014 of the Dzaipi Refugee Transit Centre in Adjumani, Uganda, where many many South Sudan refugees are living

A South Sudan People's Liberation Army (SPLA) soldier is pictured during a patrol in Malakal on January 21, 2014 a few days after retaking the town from rebel fighters