Indonesians began voting on Thursday in only the third general election since the fall of the Suharto dictatorship in 1998, in a poll that will decide who can run for president in July.

Suharto's resignation amid protests and financial ruin after three decades in power heralded the start of the "Reformasi" era of political change, and today's vote is seen as another key test for Indonesia's young democracy.

"Our polling stations are now open for the Indonesian elections. We are waiting for voters to arrive," said electoral official Enos, of Timika, Papua.

The mainly Muslim country's 171 million eligible voters are being asked to choose between thousands of candidates on local, provincial and national levels, across 520,000 polling booths and some 6,000 inhabited islands.

Polls opened at 7:00 am (0330 IST) in the restive eastern province of Papua, where police are on alert after a series of demonstrations calling for independence and a boycott of the vote.

Papua and western Aceh province -- where a three-decade separatist war ended in 2005 -- are two hot spots for potential trouble during the election but most analysts predict the day will pass in relative peace.

President Susilo Bambang Yudhoyono's Democratic Party is leading most opinion polls, well ahead of its more established rivals in the main opposition Democratic Party of Struggle (PDI-P) and Golkar, Suharto's former ruling party.