Previous promises of releases have proved disappointing

Sudan has been accused of backing a Ugandan rebel group, the Lord's Resistance Army (LRA), which in turn has been accused of abducting thousands of children and then using them as child soldiers or sex slaves.

However correspondents say it is not the first time that such hopes have been raised: Very few abducted children have been returned since a previous agreement between Sudan and Uganda signed last December.

Report to conference

Canadian Foreign Affairs Minister Lloyd Axworthy said that Sudan had agreed "to take all measures to ensure the unconditional release" of the abducted children.

"Mary" was one of the LRA's sex slaves

At the same time, he said, Uganda "will take all measures to engage in dialogue with the Lord's Resistance Army" to allow for the amnesty and rehabilitation of its members.

Canada and Egypt are to monitor the return of the abducted children and report back to an international conference scheduled for January.

Mr Axworthy said that 16 children would be released from Sudan for repatriation to Uganda on Sunday.

However he was unable to confirm whether the accord would lead to the release of all of the 6,000 Ugandan children estimated by the United Nations Children's Fund (Unicef) to have been abducted.

Small step forward

Sudanese Foreign Minister Mustafa Osman Ismail refused to respond to direct questions about the captive children at the conference.

And Mr Axworthy himself described the accord as only a small step forward and not the significant breakthrough that he had been hoping to achieve.

The children's fate is mired in regional tensions

Correspondents say it is unclear whether the agreement is likely to be any more successful than that brokered between Sudan and Uganda last December by former US President Jimmy Carter.

Within months, after the return of only a few dozen children, Uganda's President Yoweri Museveni was accusing Khartoum of backsliding on the accord.

The LRA, one of Africa's most notoriously brutal rebel groups, has long been condemned by Unicef and human rights groups such as Amnesty International.

But correspondents say that it thrives on the regional tensions caused by the Sudanese civil war, in which Khartoum's alleged support for the LRA is linked with Uganda's support for the southern Sudanese rebels.

And they say it is not clear whether Sudan is able, even if it were willing, to ensure that the LRA returns all the abducted children.