West African mediators say they will abandon their mission in the Ivory Coast if the government again fails to sign a ceasefire with rebels.

The mediators, including six foreign ministers, had flown halfway across the country for the signing ceremony on Saturday, only to discover that there was no government official present who was authorised to sign the document.

The BBC's Paul Welsh, who was on the plane, said ministers were very frustrated, and the Ghanaian envoy accused the government of "foot-dragging".

The mediators say they will leave the country if the signing, now scheduled for Sunday after setbacks on Friday and Saturday, is cancelled for a third time.

The ceasefire is aimed at ending an uprising which started on 19 September and which has claimed hundreds of lives and left thousands displaced.

Rebel demands

Our correspondent says the government only agreed to talks under pressure from the mediation teams sent by neighbouring countries and has been preparing for an offensive to recapture the rebel-held north.

The rebels have been calling for the overthrow of President Laurent Gbagbo and for fresh elections in which all political parties would be allowed to participate.

Many of the rebels come from the largely Muslim north of the country and have long complained of discrimination by Christian southerners.

Sunday's ceremony is supposed to take place in Tiebissou, effectively the front line since rebels took control of northern areas 17 days ago.

Mediators were deployed in the hope of stopping the violence escalating into a full-blown civil war.

However, correspondents say it remains unclear whether either side would stick to the ceasefire, were it ever to be signed.