East Timor's presidential elections may require a second round of voting, a top election official said Tuesday, setting the stage for prolonged instability in a young nation that nearly descended into civil war a year ago.

Prime Minister Jose Ramos-Horta, who won the 1996 Nobel Peace Prize for championing East Timor's struggle to end decades of brutal Indonesian rule, initially had been seen as the favorite for the five-year presidency.

But the 57-year-old statesman, who faced seven challengers, acknowledged he may have lost support after taking over a transitional government dominated by rival politicians.

An outright majority is needed to avoid a runoff which — together with more crucial parliamentary elections in June — could prolong tensions in the country of less than 1 million people.

Election Commission spokesman Martinho Gusmao said that with 20 percent of votes counted, the top contenders, Ramos-Horta, an independent, and Fernando "Lasama" de Araujo, of the Democratic Party, were running neck-to-neck.

"So far we see from one candidate to another there is a small difference," he said, setting a provisional date of May 8 for a run-off vote. "Perhaps no candidate will win more than 50 percent."

East Timor was heralded as a success in nation-building when it formally declared independence in 2002. Yet it descended into chaos last year after then-Prime Minister Mari Alkatiri fired a third of the tiny army, provoking gunbattles between rival security forces that spiraled into gang warfare and looting.

At least 37 people were killed and some 155,000 fled their homes before the government collapsed.

Peace largely returned with the arrival of nearly 3,000 international peacekeepers, but there has been sporadic unrest. Tens of thousands of refugees have yet to return home, and the country remains desperately poor, with 50 percent unemployment.

Preliminary results were expected Wednesday and the final tally April 19.

Angry protests broke out last month when Australian troops tried to capture popular rebel leader Alfredo Reinado in a raid backed by Ramos-Horta. Reinado escaped, but four of his followers were killed.

Ramos-Horta also has been criticized for failing to imprison former Interior Minister Rogerio Lobato, accused of helping arm civilian militias during last year's unrest.

"If I win, I will bear a wooden cross almost as heavy as Christ's," said Ramos-Horta, who claimed he would prefer to retire, write books and travel. "If I lose, I will win my freedom."

East Timor was a Portuguese colony for more than three centuries before it was invaded by Indonesia in 1976. Insurgents spent the next 24 years fighting the occupation, a struggle Ramos-Horta championed from exile.

When its people voted for independence in 1999, Indonesian troops and their militia allies went on a rampage, killing more than 1,000 people and razing Dili to the ground.