South Sudan agrees to ceasefire

South Sudan's government and rebels have signed a ceasefire, but analysts warn that bringing battling gunmen on the ground under control and making the truce stick is far from guaranteed.

Weeks of war in the impoverished young nation is feared to have spiralled out of the control of the political leaders, who themselves bickered for weeks to agree even a first stage deal, signed late on Thursday in a luxury hotel in neighbouring Ethiopia.

But even as the ceasefire was signed, government delegation head Nhial Deng Nhial said he was sceptical of the rebels' capacity to rein in their forces, 'given that the bulk of the rebels are made up of civilians' - essentially any one of the countless people who have kept hold of their guns after decades of conflict.

The fighting has seen waves of brutal revenge attacks, as fighters and ethnic militia use the violence to loot and settle old scores, with the United Nations and rights workers reporting that horrific atrocities have been committed by both sides.

Finding a deal for lasting peace - and implementing that on the ground - will be the hard part.

'Anything that stops the fighting is welcomed, but it is obvious to say, implementation is key, and past deals in South Sudan have remained little more than ink on paper,' said a Western diplomat.

'These two sides have gone so far in a few short weeks ... it was hard enough to get the delegations in Ethiopia to the table, let alone those who have been doing the actual fighting.'

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.

There will be no quick fix: billions of dollars worth of international aid, advice and development help were already poured in to the fledgling nation after the end of civil war with Sudan in 2005, but that cash apparently did little to prevent the terrifyingly swift collapse of the state.

Even for the most careful watchers of the complex power struggles of South Sudan, the conflict - and its brutal nature with neighbour turning on neighbour - were shockingly fast.