A special Nigerian tribunal has upheld last year's election of President Umaru Yar'Adua, rejecting legal challenges from the two main opposition candidates.
A five-judge panel ruled Tuesday that former military ruler Muhammadu Buhari and former Vice President Atiku Abubakar had failed to substantiate their allegations of election irregularities.
Judges said at the conclusion of the ruling that Mr. Yar'Adua remains president and Goodluck Jonathan remains vice president of Nigeria.
President Yar'Adua praised the ruling as "a victory for Nigeria's democracy and rule of law."
Mr. Yar'Adua was given a landslide victory in last April's election, which international observers said was flawed. His challengers have the right to appeal to Nigeria's Supreme Court and are likely to do so.
Armed guards were deployed in most parts of the capital, Abuja, before the ruling, following police reports alleging plans by the opposition to cause violence.
On Monday, Abubakar called on his supporters to remain calm regardless of the ruling.
Buhari and Abubakar alleged a number of election violations, including an incorrect numbering of ballot papers.