International observers say Sudan's first multi-party elections since 1986 were marred by logistical problems and by voter intimidation.
The European Union monitoring mission in Sudan and former U.S. President Jimmy Carter said Saturday that the elections fall short of international standards because of widespread problems.
The EU said 60 percent of voters turned out for the five-day vote, but observers reported a series of problems, including intimidation, incomplete voter lists and a shortage of voting materials.
Opposition groups have also complained. Several parties partially or fully boycotted the vote, including southern Sudan's main party - the Sudan People's Liberation Movement. And some groups accused the ruling National Congress Party of planning to rig the results.
Final results are expected to be announced Tuesday. Incumbent president Omar al-Bashir is expected to win another term in office.
Despite the criticism, a delegation from the European Parliament said the vote still represented a crucial step forward.
The African Union also praised Sudan for the peaceful nature of the vote.
Some Sudanese officials defended the election Saturday, saying it was unfair to expect Sudan to meet international standards. A member of the National Elections Commission said officials had done their best for a war-torn country with little electoral experience.
The elections were set up under a 2005 peace deal that ended a 21-year civil war between the Muslim north and the Christian south.
President Bashir has ruled Sudan since a 1989 coup. He was indicted by the International Criminal Court in 2008 for alleged war crimes against civilians in Sudan's Darfur region.
Southern Sudan is due to hold a separate referendum early next year on whether to become an independent country.
Some information for this report was provided by AP, AFP and Reuters.