BBC confirms that the president is alive!

Nigeria's president, not seen since going into hospital in Saudi Arabia for heart treatment in November, has told the BBC he hopes to resume his duties.

In his first interview since then, Umaru Yar'Adua said he was recovering and hoped to make "tremendous progress" which would enable him to return home.

Nigerian opposition parties have been demanding evidence about the true state of Mr Yar'Adua's health.

A rally has been called for Tuesday, mainly to protest over his absence.

There are three different court cases under way calling for power to be transferred to the Vice-President, Goodluck Jonathan.

Mr Yar'Adua is also known to have kidney problems.

'Save Nigeria'

Speaking by telephone, Mr Yar'Adua said he was making a good recovery.

"At the moment I am undergoing treatment, and I'm getting better from the treatment. I hope that very soon there will be tremendous progress, which will allow me to get back home," he said.

"I wish, at this stage, to thank all Nigerians for their prayers for my good health, and for their prayers for the nation."

Rumours had been rife that he was critically ill and unable to return to the presidency.

Under the banner Enough Is Enough, an organisation called the Save Nigeria Group called people on to the streets of the capital, Abuja.

There is a perceived danger of a power vacuum in a country which only saw the back of military rule just over 10 years ago, the BBC's Will Ross reports from the city.

The opposition plan is to march to the national assembly where senators are expected to be discussing the president's health.

Prominent opposition politicians and lawyers, Nobel laureate Wole Soyinka and the Biafran secessionist leader, Chief Emeka Ojukwu, will be among the demonstrators.

It is not clear if the demonstration will be well attended, our correspondent says.

Nigerians may be worried about their absent president but whether they will take time off to demonstrate is another matter, he adds.