(Adds comment by Prabowo's brother)
By Kanupriya Kapoor and Dennys Kapa
JAKARTA, July 10 (Reuters) - Indonesia's likely next president, Joko "Jokowi" Widodo, warned on Thursday against tampering with ballots ahead of a final count of votes from a disputed election.
Both Jokowi and his rival, former general Prabowo Subianto, claimed victory in Wednesday's election, the closest ever in the world's third biggest democracy and biggest Muslim nation with a history of deadly political violence.
The Elections Commission is to announce the official result around July 22.
"We ask everyone's cooperation to now safeguard the election result from yesterday until the official result by (the Elections Commission)...," Jokowi, who was named the election winner by several non-partisan pollsters who have been accurate in the past, told a news conference.
"I would ask everyone not to taint the sincerity of Indonesian society's aspirations in the election," he said, a clear reference to fears of doctoring votes that were cast.
Prabowo has accused his opponent of jumping the gun by claiming victory before the final count. His side has cited other unnamed quick counts which show him ahead.
Speaking to foreign reporters, his tycoon brother and chief political aide Hashim Djojohadikusumo, accused the Jokowi camp of being "highly irresponsible and highly provocative" in announcing victory so soon after polls had closed.
"We feel democracy is in serious, serious danger of being hijacked by the other side," he said, adding he was worried by possible violence and cheating during the official vote count.
Indonesia, Southeast Asia's biggest economy and a member of the G-20 group of nations, was swept by bloodshed in which hundreds of people were killed when strongman ruler Suharto was ousted in 1998 after more than three decades in power. It has since made a slow transition to full democracy, with this only its third direct presidential election.
The quick vote counts are done by private agencies approved by the Elections Commission which collate actual vote tallies as they come out of each district. But the results are unofficial.
On Wednesday night, President Susilo Bambang Yudhoyono urged both candidates to keep their supporters in check during the agonising wait for the official result.
About 250,000 police were on alert across the sprawling archipelago, the world's fourth-most populous nation, but there were no reports of violence.
Home to the world's largest Muslim population, much of Indonesia is engaged in the Ramadan fasting month when followers of the religion are exhorted to focus on spiritual matters.
"In my opinion the country is now divided into two camps .... We leave it to the Election Commission now to announce the results. I don't expect to see violence because we've been told to keep calm," said Johan, 45, in the West Java capital Bandung.
West Java, Indonesia's most populous province, was seen as a key battleground for the election and where conservative Islamic parties backing Prabowo hold much sway. But some quick counts showed that Prabowo only won the province by a narrow margin.
MARKETS BELIEVE JOKOWI WON
Indonesian financial markets surged in the belief that the unassuming Jokowi, who is seen as a representative of the common man and the face of reform, had won.
His opponent Prabowo is seen as a last gasp of the old guard and his nationalist rhetoric and suggestions of a greater state role in the economy has worried many investors.
Jakarta stocks rose to a one-year high on expectations and the rupiah also strengthened against the dollar.
"We expect investors (particularly foreign) to start pricing in a Jokowi win immediately and both bond and equity markets along with the rupiah should do well," Jakarta-based brokerage Trimegah Securities said in a research note.
The Jakarta Stock Exchange climbed more than 2 percent to an intraday high of 5,165.42 by 0234 GMT, the highest since May 30, 2013. The market is up nearly 20 percent so far this year.
The rupiah also rose, climbing to a seven-week high against the dollar at 11,520 despite the uncertainty.
"It seems like the market will rise in the next couple of days, but it may not sustain the gain until there is an official result from the KPU," said Jeffrosenberg Tan, a director at Sinar Mas Asset Management, referring to Indonesia's Elections Commission.
The latest presidential race was the dirtiest and most confrontational in a country which traditionally holds up the value of consensus politics.
Jokowi took an early step onto the international political stage by condemning Israel's offensive in Gaza. Indonesia has long supported the Palestinian cause and does not have diplomatic relations with Israel.
"Israel's attack on the Gaza Strip...is a violation of human rights," he said.
($1 = 11,620 rupiah) (Additional reporting by Lewa Pardomuan in Bandung and Jonathan Thatcher; Writing by Randy Fabi; Editing by Jonathan Thatcher and Mark Heinrich)