Algerian President Abdelaziz Bouteflika, the independence veteran in power for 15 years, won re-election Friday with more than 80 percent of a vote that opponents dismissed as fraud to keep an ailing leader in power.

Bouteflika had cast his vote sitting in a wheelchair Thursday in what was a rare public appearance since suffering a stroke last year that raised questions about stability in the North African OPEC oil-exporting state.

The Algerian leader, 77, was already widely expected to win with the backing of the powerful ruling National Liberation Front, which has dominated the political system since independence from France in 1962.

Preliminary official results showed Bouteflika had won with 81.53 percent of the vote, Interior Minister Tayeb Belaiz told a news conference. His nearest rival, Ali Benflis, won 12.18 percent, and national turnout was 51.7 percent.

"The victory confirms Bouteflika can give more to Algerians in the next five years," former Premier Abdelmalek Sellal told a news conference, with a framed portrait of Bouteflika placed on a stand next to him.

But the aging leader's health has left more questions about possible transition in Algeria, who would replace him should he fall ill in his fourth term, and how far the new government will go toward introducing political and economic reforms.

Six opposition parties boycotted Thursday's vote, saying it would not reform a system mostly closed to change since the FLN's one-party rule in the early post-independence years.