Communist party of Nepal (Maoist) president Prachanda gestures after winning his seat in recently held elections, in Katmandu, Nepal, 12 Apr 2008

Nepal's former Maoist rebels have taken a surprising early lead in election results for a special assembly that will rewrite the country's constitution.

Election officials say the Maoists have won 11 of about 20 constituencies where results have been declared, with one of the seats going to Maoist leader Prachanda.

Officials also say the Maoists are leading in about half of some 120 other constituencies where ballot counting is underway.

Hundreds of Maoist supporters celebrated the early wins by chanting Maoist slogans and displaying the party's hammer and sickle symbol Saturday in the capital, Kathmandu.

A complete vote count from all 240 constituencies is expected to take several weeks.

Nepal is choosing a 601-seat special assembly that is expected to abolish the world's last Hindu monarchy.

The Maoists' early gains put them ahead of their main rivals - the Communist Party of Nepal-UML and the Nepali Congress party.

One of the top election observers, former U.S. President Jimmy Carter, says the voting Thursday was free and fair with some minor discrepancies.

But the head of one of the most visible observer groups, the Asian Network for Free Elections, Damaso Magbual, says a declaration the voting was free and fair must wait until re-polling is conducted in problem areas and the votes are re-counted.

Nepalese officials and international observers say Nepal's first election in nine years was relatively peaceful with few incidents of violence or irregularities.

Sporadic violence killed at least two people on election day, including one candidate. At least eight people were killed in campaign-related violence in the days leading up to the vote.

Some information for this report was provided by AFP, AP and Reuters.