Nigerian diplomatic sources say President Umaru Yar'Adua will be discharged from hospital in Saudi Arabia in the very near future.

It is sill not clear when he will return to Nigeria, but diplomats say his health has considerably improved. The president went to Saudi Arabia in November to be treated for heart problems.

His absence has led to constitutional problems in Nigeria, with doubts being raised as to whether Vice President Goodluck Jonathan could act as president. On Wednesday, the High Court ruled that he could, but that he should not be named interim president. There was widespread dissatisfaction with the ruling.

Nigeria's ethnic divide lay behind the dispute about whether the vice president could stand in for Mr Yar'Adua. The president is from the predominantly Muslim north, while Mr Jonathan is from the mostly Christian south. Relations between the two parts of the country are tense.

photo: Umaru Yar'Adua (flickr / World Economic Forum)