PORT-AU-PRINCE, Haiti - Michel Martelly, a carnival singer with a colorful past who seized the mantle of change, is Haiti's new president after storming to a landslide victory, preliminary results showed.

The 50-year-old faces the huge challenge of rebuilding the Caribbean nation, which was the poorest country in the region even before a January 2010 earthquake flattened the capital Port-au-Prince and killed more than 225,000 people.

Martelly, with 67.57 percent of the vote, ended the dreams of former first lady Mirlande Manigat, who was vying to become Haiti's first democratically elected female leader but finished with a disappointing 31.74 percent showing.

The results, released late on Monday by the electoral commission, are not final as a period of legal complaints must be observed until April 16. But with such a large margin, Martelly's victory seems all but assured.

His supporters engaged in peaceful celebrations on the streets of the capital's Petionville area, though the US embassy reported gunfire from the festivities and urged its citizens to "stay indoors and avoid large crowds for tonight".

Washington hailed the election results as an "important milestone" and urged Haitians to keep their demonstrations peaceful as the process moves forward.

It was an amazing turnaround for "Sweet Micky", who was knocked out of the race in December only to be reinstated a month later after international monitors found massive fraud in favor of the ruling party candidate.

The bawdy entertainer was previously known for stripping and for ridiculing the government in satirical stage performances.

But trading skirts for tailored suits, he led a slick campaign that succeeded in capturing the imagination of Haiti's urban youth, the main voting block in a country where the average age is just 21.

He should now take office on May 14, after President Rene Preval, who has served the maximum of two terms allowed by Haiti's constitution, steps down.

Martelly has promised to tackle Haiti's institutional failings and counter its dependency on NGO handouts. He has also indicated he is eager to bring back the military, disbanded in 1995 after a history of coups and abuse.

More than 14 months after the earthquake, hundreds of thousands of survivors subsist in squalid tent cities, unemployment hovers around 50 percent and three in four Haitians live on less than $2 a day.

Agence France-Presse