Nigeria's opposition wants the presidency to "come clean" on President Umaru Yar'Adua's health. The Nigerian leader is in Saudi Arabia for medical examinations.

The main opposition Action Congress urged Nigerians to, as it put it, "pray fervently for the president's good health so he can face the tough task of governance."

The party is also seeking clarity on the state of the president's health, saying the presidency should come clean on the issue.

Mr. Yar'Adua, known to have a chronic kidney problem, traveled to Saudi Arabia Monday night for what his spokesman said was for a Muslim pilgrimage and a medical checkup.

Abuja-based political analyst, Maxi Okwu, says most Nigerians are concerned about the government's handling of the issue.

"The president of Nigeria is a public figure and all that concerns him should be in the public domain," said Okwu.  "But since Umaru Yar'Adua became president they shrouded his obvious health problems in mystery. He has a health condition which he shrouded in mystery, which can only happen in a sort of caricature democracy we practice here. Some time ago, he disappeared for two weeks."

This is President Yar'Adua's third visit to the Middle East country in as many months for medical treatment, raising fears about his fitness to lead Africa's most populous nation. His supporters and the government have said Mr. Yar'Adua is in good health and fit to rule. Already, there is talk the president is likely to run for re-election in 2011. Okwu says this may not be in the best interest Nigeria.

"They should seriously advise him against going for second term in the interest of himself and in the best interest of Nigeria," added Okwu.

Before taking over from Obasanjo in 2007, Mr. Yar'Adua was a little-known governor of the northern state of Katsina.  His health has been a source of constant speculation in the Nigerian media.