The presidential and legislative polls, set up under a 2005 peace deal that ended two decades of north-south civil war, were supposed to help transform the troubled oil-producing nation into a democracy.

Bashir won between 70-92 percent of votes cast in presidential ballots in around 35 scattered polling centres, foreign voting posts and one state, said state news agency Suna.

Those figures represent a fraction of the country and have not been confirmed by authorities.

Separately, Sudan's National Elections Commission began to announce the first official results of the contest on Sunday -- 17 state assembly seats from north Sudan all of which went to Bashir's National Congress Party (NCP) with massive majorities.

Senior NCP official Rabie Abdelati told Reuters he was expecting similar results across Sudan.

"This victory is a real victory ... The counting of the votes took place under the sun, not in a dark room. The observers saw everything," he said.

Opposition groups said the huge majorities proved their accusations that the NCP had fiddled with ballot boxes in the north, justifying the decision of many parties to boycott. They say they caught officials exchanging and stuffing ballot boxes at night during the five-day voting process.