Indonesia's incumbent president looks to be heading for re-election after the country went to the polls Wednesday.

Joko Widodo was running against rival candidate Prabowo Subianto in the general election, although official results will be released in May.

He is expected to have secured 54 to 56 percent of the votes while the former army general Prabowo has managed between 43 and 45 percent, according to unofficial projections carried out by pollsters.

The results were reported hours after the closure of the polling stations and represent predictions from 40 independent companies approved by the General Elections Commission of Indonesia.

More than 192 million Indonesians went to the polls to choose between Widodo, representing the continuity of social policies and who has a moderate profile, against the protectionist and nationalist policies of Prabowo.

During the campaign, both candidates defended their Islamic credentials in a country with the largest Muslim population in the world - 88 percent of its more than 265 million residents – and which has seen a rise in conservative Islam in recent years.

Widodo belongs to the Indonesian Democratic Party of Struggle, which occupies 109 of the parliament's 560 current seats, while Prabowo belongs to the Great Indonesia Movement Party which occupies 73.

In addition to electing the president and vice president, voters will also elect members of 575 seats of the lower house, 136 of the upper house, and representatives to the provincial and municipal legislative chambers.

Parties that do not secure at least 4 percent of the votes in parliament will not be represented in the lower house.

Millions of Indonesians voted in the world’s biggest one-day election and the General Elections Commission of Indonesia (KPU) had estimated a 77.5 percent turnout and the government had declared Wednesday a national holiday to ensure maximum voting.

Some 40 organizations have been recognized by the KPU to conduct vote projections after the preliminary results were out.

Widodo, popularly known as Jokowi, cast his vote in Jakarta shortly after Prabowo cast his in a polling station in Bogor.

After he left the polling station in the central district of Gambir, Widodo told the media that he was optimistic about the results as he and his party had worked for the people.

"I voted for Jokowi obviously," said Niar Nurdin to EFE after casting his ballot.

"In the last four years I can really see the difference in terms of infrastructure, he has focused not only in the capital but also in the suburbs, villages and under-developed regions," added Nurdin, as the queue of voters waiting for their turn grew behind him.

Indonesian elections are one of the most complex in the world, as more than 190 million voters were called to vote at 800,000 polling stations to elect from 245,000 candidates for 20,000 posts in a single day.

Another two million Indonesians living abroad were estimated to cast their votes through postal ballots.

Indonesia, a Muslim-majority country, is one of Southeast Asia's most consolidated democracies, and political analysts find little possibility of any large-scale manipulation during the voting process.

However, Prabowo a few weeks earlier reported irregularities in the electoral lists and threatened to approach the Constitutional Court unless they were addressed.