(Bloomberg) -- At least six people have been killed and hundreds more injured in clashes between police and supporters of Indonesian presidential candidate Prabowo Subianto after a post-election rally turned violent.

Jakarta Governor Anies Baswedan appealed for public order and urged law enforcement personnel to exercise restraint and avoid conflict with the protesters. About 200 injured protesters have been admitted to various hospitals in Jakarta, Baswedan told reporters.

Protesters set fire to a police building in central Jakarta early on Wednesday after police fired tear gas to disperse the crowd outside the nation’s election supervisory board late on Tuesday, Kompas TV reported. A group of people also clashed with the police in several other parts of the capital, hurling stones and petrol bombs, Tirto.com reported.

The police will deal firmly with protesters breaking the law and have detained several people in East and West Java as a precaution, Dedi Prasetyo, a spokesman for Jakarta police, said on Kompas TV. Supporters of Prabowo, as Subianto is commonly known, have threatened to rally outside the nation’s General Elections Commission and the poll watchdog on Wednesday as well to protest the official result confirming incumbent Joko Widodo’s as the winner of April 17 election.

Widodo, known as Jokowi, won the presidential race with 55.5% of the national vote, the commission said on Tuesday, an outcome rejected by Prabowo, who has threatened a court challenge. The former general has repeatedly claimed victory, citing his own team’s survey of votes, and alleged the commission had made no effort to address complaints of election irregularities.

Challenging Outcome

“There’s a lot of people who absolutely and sincerely support Prabowo and his coalition of parties and are very disappointed with the result,” said Greg Barton, a professor of global Islamic politics at Deakin University in Australia. “Given the momentum behind the desire to protest, given Prabowo’s commitment and given his resources, there was always going to be a bit of venting.”

A candidate can challenge the result in the nation’s Constitutional Court within three days of the declaration of the official result, according to election rules. Prabowo, who lost to Jokowi in the 2014 elections, had challenged the outcome only to be rejected by the court.

Indonesia’s stocks, bonds and currency markets weren’t affected by the rioting though several schools remained shut and some companies allowed employees to work from home.

Police, which have been placed on the highest security alert nationwide until May 25, have urged people not to participate in rallies because militants linked to the Islamic State were plotting to use the gatherings to launch attacks.

Prabowo’s campaign team called for calm and urged police to exercise restraint. Dradjad Wibowo, a spokesman for the team said it stood by its demand for an independent campaign investigation into the claims of vote-rigging.

“We cannot dismiss the accusation of vote rigging just like that," Wibowo said. “The claims have to be investigated independently by a group agreed by both sides that has the power to get all the details. It’s very important. Without that it will be very difficult to get reconciliation.”

Jokowi has called for peace and unity, urging citizens to respect the will of the people and the democratic process. The president said he respected his opponent’s decision to challenge the verdict and pledged to “work hard to realize social justice for all Indonesians.”

Jokowi, 57, is expected to be sworn in for his second five-year tenure on Oct. 20.

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--With assistance from Yoga Rusmana, Fathiya Dahrul and Harry Suhartono.

To contact the reporters on this story: Karlis Salna in Jakarta at ksalna@bloomberg.net;Tassia Sipahutar in Jakarta at ssipahutar@bloomberg.net;Arys Aditya in Jakarta at aaditya5@bloomberg.net

To contact the editors responsible for this story: Thomas Kutty Abraham at tabraham4@bloomberg.net, Rieka Rahadiana

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