By Joseph Guyler Delva and Pascal Fletcher
PORT-AU-PRINCE (Reuters) - Haitians voted on Sunday to elect a president for their poverty-stricken and earthquake-scarred country, choosing between an extrovert singer and a former first lady in a scrappy run-off ballot.
Delays and missing materials hampered voting in the scruffy capital Port-au-Prince, and U.N. peacekeepers intervened in scattered incidents across the nation, firing in the air in one place to separate feuding rival supporters.
But the U.N. Mission in Haiti (MINUSTAH) described the security situation during voting as "generally OK," an apparent improvement over the chaotic first round vote in November which was marred by confusion, fraud allegations and unrest.
International donors hope the run-off vote in the small Caribbean state, one of the poorest nations in the world, can elect a capable, legitimate leadership to steer a post-quake reconstruction that requires billions of dollars of aid.
"So far, so good. Let's keep our fingers crossed," MINUSTAH spokesperson Sylvie van den Wildenberg said.
The election presented Haiti's 4.7 million voters with a choice between a political newcomer, energetic entertainer and singer Michel Martelly, 50, and former first lady Mirlande Manigat, 70, a law professor and opposition matriarch.
Many polling stations in the capital were initially unable to open on time because materials such as ink to mark voters' fingers, ballot papers, labels to mark the ballot boxes and sometimes the boxes themselves had not arrived.
But as the morning progressed, these glitches were mostly resolved, van den Wildenberg said.
Some polling stations serving residents from the Cite Soleil slum were primitive -- voters deposited their ballots in boxes placed on the floor or on crude concrete blocks.
Casting his vote in the capital, outgoing President Rene Preval appealed for calm, calling the presidential vote, the first second round run-off in Haiti's electoral history, an important step to consolidate the country's democracy.
"I hope the day will go well, that the results won't have any trouble, so we can have an elected president to replace me," he told reporters.
Martelly was mobbed by cheering supporters when he voted in the Petionville district. His rival Manigat voted in the Delmas neighborhood.
The run-off was expected to be close-fought, but recent opinion polls have shown Martelly slightly ahead of Manigat.
"HOPING FOR A BETTER LIFE"
Blue-helmeted Brazilian U.N. troops guarded voting centers in Port-au-Prince along with Haitian police. White U.N. armored vehicles rumbled through the streets, many still strewn with debris left from last year's quake.
"I need a president to change the situation of the country," said Adeline Hyppolite, 50, a voter in Petionville.
"We are hoping for a better life ... but only God knows," she added, saying her husband had been disabled in the quake.
A confused incident on the eve of the vote involving Haitian-American hip hop star Wyclef Jean, who backs Martelly, led to an erroneous report that he had been shot in the hand.
But Vanel Lacroix, police chief in Petionville where Jean is staying, said police had confirmed that he had suffered only a minor cut to his hand from glass in an apparent accident.
Sunday's run-off followed a turbulent November 28 first round vote that dissolved quickly into fraud allegations and unrest.
U.N. Secretary-General Ban Ki-moon and other international leaders appealed for a calm, transparent run-off vote.
Weighing on many Haitians' minds as they voted was the reappearance of former President Jean-Bertrand Aristide, who arrived back from exile on Friday.
The return of the left-wing populist who still commands a big following in Haiti was opposed by the United States and United Nations as potentially disruptive. But Aristide is not a candidate and aides have said he will stay out of politics.
Aristide, who was driven into exile by a 2004 rebellion, has not clearly endorsed any candidate.
Mixed in with banners welcoming Aristide, the dueling slogans of the rival candidates were plastered on walls.
Martelly's "Tet Kale" slogan, a Creole play on words that refers to his shaven head and also means "all the way" to convey his promise of forceful change, contrasts with Manigat's more homely "Banm Manman'm" (Give me Mummy) slogan that seeks to bolster her image of experience and responsibility.
Many voters said if Aristide, revered by many as a champion of the poor, were a candidate, they would vote for him.
Under Haiti's election law, the Provisional Electoral Council is due to announce preliminary results from the run-off on March 31, with final results being confirmed on April 16.
(Additional reporting by Faradjine Alfred; Editing by Vicki Allen)