In pictures: Sudan votes in key poll

Men line up outside polling station at local school in Sudan

As Sudan held its first multi-party polls since 1986, 16 million people are registered for the presidential, parliamentary, regional and state elections.

A woman bends to search for her name on a voting list

A woman bends over to search for her name on a voting list. The process is complex, with some Sudanese people in the south having to cast 12 different votes.

A Sudanese woman picks up a ballot paper before voting

As Sunday's voting got underway, polling centres were in disarray as they found voters using the wrong ballot paper or names or symbols were incorrect.

Election observers have reported irregularities by the president's supporters. But many Sudanese were happy to have the opportunity to vote, despite the complaints.

A man wearing a picture of President Omar al-Bashir on his t-shirt

A man demonstrates his allegiance to President Omar Hassan al-Bashir and his National Congress Party. Mr Bashir, who is wanted by the UN for alleged war crimes, is widely expected to win.

Sudanese man marks vote in election booth

The country's national election commission claims the polls will be free and fair. One official described the process as "foolproof".

Women outside a polling station at a refugee camp in Sudan

Women vote in a refugee camp on the outskirts of the Darfur town of Fasher. Some Sudanese, not familiar with the process, were afraid to dip their finger in ink after casting their votes.

Soldiers sit outside polling station in Sudan

Opposition figures complained that election officials had allowed Sudan's numerous security forces to register to vote at their barracks. They claimed their presence would intimidate voters.