* President facing little-known challenger
* Expected to easily gain second term
* Opposition call for boycott, complain of oppression
* Credible contenders withdraw (Adds polls closing, paragraph 6)
By Mahmoud Mourad, Ahmed Aboulenein and Eric Knecht
CAIRO/ALEXANDRIA, March 26 (Reuters) - Egyptians began voting on Monday in a presidential election that guarantees victory to President Abdel Fattah al-Sisi, running virtually unchallenged with all credible candidates intimidated or locked up.
Sisi, who appears to see the vote more as a referendum on his rule than a serious democratic contest, has urged Egyptians to vote, hoping a large turnout will give him a mandate to repair the economy, crush Islamists fighting to topple him and revive Egypt’s diminished regional clout.
Opposition figures have called for a boycott, while the president’s sole challenger is Moussa Mostafa Moussa, a Sisi supporter widely seen as a dummy candidate.
Sisi’s top potential challenger, influential former military chief of staff Sami Anan, was arrested and halted his presidential bid; another serious contender, ex-prime minister Ahmed Shafik, dropped his campaign, apparently under pressure.
Egypt’s election commission said the election would be free and fair, and Sisi said he would have liked more candidates running.
By evening, turnout among the 59 million eligible voters appeared low. Polls closed at 9 p.m. (1900 GMT) but there are two more days for Egyptians to cast votes, with official media hammering the message that voting was a national duty to foil the country’s “enemies”.
Sisi, an ex-general who in 2013 led the military overthrow of Egypt’s first democratically elected president, Mohamed Mursi of the Muslim Brotherhood, is trying to defeat Islamist insurgents in the Sinai Peninsula and complete a series of mega-projects inaugurated with great fanfare since he came to power.
Those who cast ballots said they were voting for stability.
“If it weren’t for Sisi, Egypt would have become like Iraq, Yemen, Syria and Libya - they (Islamists) would have destroyed the country,” said Fayez Amin, 72, tourism worker, who voted in the upscale Cairo neighbourhood of Zamalek.
“Without Sisi you wouldn’t be able to be here,” he told a Reuters reporter.
“If it weren’t for Sisi, the country would have collapsed. He is clearing the country of terrorists,” said Sayed Kamel, who runs a bookshop.
In the northern Sinai Peninsula, locked into a fight between the army and Islamist militants, officials overseeing voting said there was minimal turnout as many residents feared leaving their homes would expose them to an attack.
Islamic State’s Sinai branch warned Egyptians against voting in an apparent threat weeks ahead of the election.
The vote follows the heaviest crackdown in decades on dissent, targeting not only Islamists but also secular and liberal activists. Hundreds of Brotherhood members and leaders have been locked up, critics muzzled and websites blocked.
Secular opposition figures also urged Egyptians to stay away from the polls.
“I’m boycotting the elections because it’s clear there aren’t actually elections, it’s simply a referendum on the ruling regime...All the opposition candidates that had popularity or national support are in jail,” said Ahmed Saad, a leader within the liberal Ghad al-Thawra Party, in Alexandria.
Another voter lamented the election’s lack of choice.
“There’s no real competition or diversity of choice,” a 42-year-old man in Alexandria said, without giving his name for fear of reprisal by authorities.
In poorer neighbourhoods, where residents have been hard hit by inflation, there appeared to be less interest in voting. In the working-class Cairo neighbourhood of Sharbiya there were voting stations with only a handful of voters and none with more than 10 individuals waiting in line, a Reuters reporter said.
In Cairo’s Rabaa square, the scene of a bloody crackdown on the Muslim Brotherhood in 2013, few voters appeared, mostly elderly admirers of Sisi.
Amr Darrag, a Brotherhood leader in exile, urged Egyptians not to vote, saying in a tweet they should not give legitimacy to Sisi because he had “usurped” power.
Large numbers of police and soldiers deployed at polling stations a day after a bomb attack that targeted a security chief in the northern city of Alexandria.
TIMELINE: Egyptian since Arab Spring uprisings
A lower-than-expected turnout could suggest Sisi lacks a mandate to take more of the tough steps needed to revive the economy, which struggled after the 2011 revolution drove away tourists and foreign investors, both sources of hard currency.
Reuters reporters in Cairo and other provinces saw groups of Sisi supporters waving the Egyptian flags, dancing to nationalist songs and raising the victory sign.
One of the few young voters at a Heliopolis polling station, Zeina Sherif, 20, said: “Sisi is working on projects that we should give him a chance to finish.”
These projects include an expansion of the Suez Canal and a new capital being built east of Cairo. These will in time improve the economy and people’s lives, Sisi says.
But critics say austerity measures have hurt his popularity, including a currency devaluation tied to an International Monetary Fund loan which left most Egyptians worse off. Many see little benefit from large projects and the harsh fiscal reforms.
Several politicians called for a boycott of the vote weeks ago after all major opposition campaigns withdrew, saying repression had cleared the field of credible challengers.
West of Cairo, a young woman who also declined to give her name said: “This is not a democratic exercise. We don’t have any freedom of choice, or freedom of expression.”
Sisi has said he will not seek a third term, but critics expect him to remove a two-presidential term limit.
He won nearly 97 percent of the vote in 2014, but less than half of eligible Egyptians voted, even though the election was extended to three days.
Reporting by Mahmoud Mourad and Ahmed Aboulenein in CAIRO, Eric Knecht in ALEXANDRIA; Additional reporting by Ahmed Tolba, Arwa Gaballa, Samia Nakhoul, Laila Bassam, John Davison, Mohamed Abdellah, and Mostafa Hashem in CAIRO, Nadine Awadalla in ALEXANDRIA, and Amina Ismail in MINYA; Editing by William Maclean/Mark Heinrich