In Khartoum, turnout was lighter than expected in the first few hours of voting, aside from a few enthusiastic supporters of President Omar al-Bashir.

The elections, which will run through Tuesday, are an essential part of a 2005 peace deal that ended the north-south war that killed 2 million people over 21 years. They are designed to kick-start a democratic transformation in the war-plagued nation and provide a democratically elected government to prepare for a crucial southern referendum next year.

But two major political parties, including the southerners, decided to pull out fully or partially from the race, saying the process lacks credibility and elections can not be held in the western Darfur region while under a state of emergency.

More than 800 international observers descended on Africa’s largest country to observe the fairness of the contests, with the largest group from former US President Jimmy Carter’s organisation. He toured a polling stations at the start of the day.

“I think (opposition parties) want to see a peaceful transition and peace in this country, so I don’t think there is any party that is threatening at all any disturbance or violence or intimidation of voters,” he told reporters. “So we do expect and hopeful and believe there will be a peaceful election.”

The opposition has made a series of complaints — that the National Election Commission is biased to the government, the ruling party has used state resources in the campaign, the number of polling stations nationwide was cut to half from 20,000.

“This is the first time that the party that carried out a coup organises elections,” said Sarah Nugdallah, head of the political bureau of the Umma party, a major northern opposition group which is boycotting.

Some 16 million people will vote for over 14,000 candidates for everything from president to local councils.

Voting took place amid heavy security and the police have issued stern warnings that no disturbances will be tolerated on the election day.