By Shadi Bushra and Khalid Abdelaziz
KHARTOUM (Reuters) - Sudanese voters trickled in to polling stations on Monday at the start of a three-day election boycotted by the main opposition parties, with President Omar Hassan al-Bashir set to extend his quarter-century in power.
The presidential and parliamentary polls are the first since Sudan saw its south secede in 2011, losing a third of its land and nearly all of its oil production.
Bashir has campaigned on improving the economy, in which inflation and unemployment remain high. He has also promised to maintain stability, warning against a change in government while the region is embroiled in violence from Libya to Yemen.
In Sudan, security forces are tackling insurgencies in the western territory of Darfur and along the border with South Sudan.
"The elections are good and clean and there's nothing more I would ask of them," said Nadia Ahmed Abdelrahman, a 55-year-old local government official voting in the capital.
"The elections are better than what is happening elsewhere in the region. Look at the death and killing. Thank God we have avoided that," she said.
But voters, who tend to head to the polls later in the day, were thin on the ground in Khartoum early on Monday.
The boycotting parties say a clamp down on the opposition, media and civil society has created an impossible environment to compete against Bashir, who has ruled since a 1989 Islamist and army-backed coup.
Bashir voted close to his residential compound, surrounded by heavy security. He waved to supporters who shouted "God is greatest" as he cast his ballot.
The European Union, which observed the last, more widely contested elections in 2010, has criticized the political environment ahead of the polls.
The boycott means voters are left to choose between Bashir's National Congress Party (NCP) and a handful of relatively new groups. Government critics say these form a token opposition that does not differ from the NCP on core issues such as security and the economy.
"Look at this place, there's no one here," said NCP supporter Abdelaziz al-Hasan, 72, gesturing at a polling station in Khartoum where there were only two other voters.
"We've seen no posters for anyone besides Bashir. We don't even know who the rest are," Hasan, a retired Ministry of Industry official, said.
"I always stand with the strong ... Why vote for someone new and weak when this government is going to fix relations with Saudi, bring some Gulf money in?"
In a diplomatic move that could unlock investment, Sudan has said it will join a Saudi-led military campaign against Iran-backed Houthi rebels in Yemen.
Analysts say this was aimed at showing Gulf powers Khartoum is a reliable partner in return for financial support. Sudan says its role in Yemen is unrelated to its economy and intended to protect holy sites in Saudi Arabia.
Initial results are expected in the days after the polls shut.
(Editing by Sylvia Westall and Andrew Heavens)