Many refugees have lost their land

"The southern provinces are not safe yet for the refugees to return," said Ivana Unluova, a spokeswoman for the UN refugee agency in neighbouring Tanzania, which hosts most of Burundi's refugees.

The BBC's Prime Ndikumagenge in the capital, Bujumbura, says that people are reserving their judgement until this week's deal between President Domitien Ndayizeye and Pierre Nkurunziza's FDD rebels is put into practice.

A ceasefire signed last December by the two sides failed to end the bitter civil war, pitting ethnic Hutu rebels against an army dominated by the Tutsi minority.

A final ceasefire... carries the risk that a great many people who were uprooted will return to a country not yet prepared to receive them Francois Grignon International Crisis Group

But the editor of the BBC's Great Lakes Service, Laurent Ndayuhurume, says the latest agreement might be different because it goes into such detail.

A smaller rebel group, the FNL, has so far refused to take part in peace negotiations and dismissed the peace agreement as a sham.

Mr Ndayizeye, a Hutu, became president in April under the terms of an earlier power-sharing agreement, which is supposed to lead to elections next year.

'Lack of planning'

In a report released just before the deal was signed, the think-tank International Crisis Group warned that not enough thought was being given to what would happen if peace took hold and the refugees returned - to find that other people were living on their land.

FDD GAINS 4 ministers 40% of army officers 15 MPs Second assembly vice-president Assembly deputy secretary general 2 ambassadors 35% of a new police force 35% of vacant secret service posts FDD fighters to be demobilised

"Lack of planning for the eventual mass return of refugees and displaced persons, and the land questions it raises, risk destabilising any transition to peace right from the outset," said Francois Grignon of ICG.

"A final ceasefire... carries the risk that a great many people who were uprooted will return to a country not yet prepared to receive them."

Some 350,000 refugees, mostly from Burundi are living in UNHCR camps in Tanzania, while the ICG says there are another 300,000 scattered across Tanzania.

An estimated 280,000 Burundians are displaced within the country.

This agreement spells out the details of how the army would be restructured - a key rebel demand.

Under the agreement, the rebels will now take up 40% of officers' posts in the army.

Politically they will be given four ministerial positions, and the vice-presidency of the country's national assembly.