SAN`A, Yemen (AP)-- Yemen's president was re-elected with more than 77 percent of votes in the face of the strongest challenge since he came to power 28 years ago from an opponent with a substantial popular following, officials said Saturday.

But the opposition alleged fraud and immediately rejected the result.

Elections commission chief Khaled Sharif said the final tally showed President Ali Abdullah Saleh received 4.1 million votes, or 77.17 percent of 5.3 million valid votes, while challenger Faisal bin Shamlan won 1.1 million votes, or 21.82 percent.

More than 6 million of Yemen's 9.2 million registered voters cast ballots on Wednesday, putting turnout at 65 percent. Tens of thousands of ballots were discarded because of voter error, he told a news conference.

Opposition parties backing bin Shamlan immediately rejected the election commission's results, claiming their candidate won at least 40 percent. A spokesman said the opposition would announce its own results Sunday. "What has been announced is not true and is illegal," said Ali al-Sarari, an opposition spokesman. "There has been tampering in the results of the elections and the regime in Yemen is still autocratic."

The elections confronted Saleh with his first serious challenge since coming to power in 1978. It was the first time in modern Arab history that a president went head-to-head with an opponent who had a substantial popular following.