(AFP) - Indonesia's Joko Widodo said Thursday his reelection as head of the world's third-biggest democracy was all but assured, calling for calm as his firebrand ex-general rival insisted he had in fact won the nation's top job.

Widodo, 57, said he had received phone calls from world leaders to congratulate him on his country's biggest-ever election, but added he would await the final results before formally declaring victory.

He cited a series of so-called "quick counts" by pollsters, which are based on samples, that showed him as much as 11 percentage points ahead of Subianto.

Quick counts have been reliable indicators in past elections.

But "we still have to wait for the numbers from the KPU (General Elections Commission)", Widodo told a crush of reporters.

"Let's continue to work and maintain our unity and harmony as a nation," he added.

However, Subianto insisted that he and running mate Sandiaga Uno, a wealthy financier, had prevailed, citing voter fraud but without supplying concrete evidence.

"Sandiaga Uno and I are declaring victory as the president and vice president," he told cheering supporters in Jakarta, ending his speech with shouts of "Allahu Akbar" (God is Greatest)" and "Merdeka" (freedom).

The retired general -- who had close ties to the Suharto dictatorship, which collapsed in 1998 -- earlier warned he would challenge the results in court if he lost, and stage street protests.

Some supporters of Subianto called for a march near Jakarta's biggest mosque after prayers on Friday, Islam's holy day.

The 67-year-old, who has long had his eye on the country's top job, lost to Widodo in 2014 and then mounted an unsuccessful legal challenge to that election.

- 'Smooth and safe' -

The competing claims came as authorities warned against unrest over Wednesday’s "smooth and safe" polls, and warned of arrests.

"If there are any illegal or unconstitutional actions that threaten public stability and security, (authorities) will take firm action," National Police Chief Tito Karnavian said Thursday.

"We won't tolerate it.

"I urge everyone against mass demonstrations, whether it's to celebrate or to express dissatisfaction" at the results, Karnavian added.

This year's campaign was punctuated by bitter mudslinging and a slew of fake news online -- much of it directed at the presidential contenders.

Authorities said Thursday they had seen a spike in false reports and hoaxes, with some calling for chaos in the streets and for Indonesians to commit violence in response to the results.

However, the capital Jakarta was quiet Thursday after as many as 190 million voters in the Muslim-majority country cast ballots in the one-day poll -- which featured a record 245,000 candidates -- to elect a new president, parliamentarians and local legislators.

Online, Subianto was pilloried by social media users who poked fun at his repudiation of the unofficial results and for kissing the ground as he declared himself president.

"We honestly feel sorry for Prabowo, not because he's lost the election (again) but because he is surrounded by people who made him a zombie who can't differentiate between reality and illusion," said one Twitter user with 165,000 followers.

National newspapers called for reconciliation, with top-selling Kompas saying "Let's Unite", while Tempo declared it "One More Time" for Widodo.

Financial markets cheered, with the Jakarta composite stock index and the Indonesian rupiah both higher.

© Agence France-Presse