Demonstrations over the outcome of last month's presidential election have gripped the heart of Indonesia's capital after an overnight face-off between police and protesters in which, according to Jakarta's governor, six people died.
The protests followed an announcement before dawn on Tuesday by the election commission confirming that President Joko Widodo had beaten his challenger, former general Prabowo Subianto, in the April 17 poll.
Crowds swelled in central Jakarta on Wednesday morning and police said they expected more protesters to join them before nightfall.
Some of those arriving carried wooden poles and some had smeared toothpaste around their eyes, apparently to protect themselves from tear gas.
The majority of the protesters appeared to have come from outside Jakarta and police found envelopes containing money on some of the people they searched, National Police spokesman Muhamad Iqbal told a news conference.
"This is not a spontaneous incident, this is something by design. There are indications that the mobs are paid and bent on causing chaos," he said.
The General Election Commission on Tuesday confirmed unofficial counts by private pollsters that gave Widodo a 55.5 per cent share of votes against 44.5 per cent for Prabowo.
Widodo won more than 85 million votes of 154 million cast in the world's third-largest democracy, but retired general Prabowo has alleged "massive cheating and irregularities".
Prabowo's legal director has said his campaign plans to contest the result in the Constitutional Court.
On Monday, an election supervisory agency dismissed claims of systematic cheating, citing a lack of evidence. Independent observers have said the poll was free and fair.
Islamist groups, many of which support Prabowo, have in the past been able to mobilise hundreds of thousands of supporters.
Presidential Chief of Staff Moeldoko said he believed there was "a systematic effort by a certain group ... that is riding on the situation to muddy the situation", adding that authorities had seized two pistols from people involved in riots.
Protests that began calmly in the sprawling textile market neighbourhood of Tanah Abang on Tuesday turned violent after nightfall, with police firing tear gas to disperse the crowd.
Jakarta Governor Anies Baswedan told TVOne that by the morning six people had died and 200 people had been wounded.
News website Tirto reported a man died of bullet wounds in Tanah Abang, quoting a doctor at a hospital near the site.
Fadli Zon, deputy chairman of Gerindra, Prabowo's political party, accused police of initiating an attack on protesters and said he found 171 bullets, including live rounds, when he visited the area on Wednesday morning.
"The public have a right to demonstrate. They are people who are concerned by cheating. They are not mobilised, paid or facilitated," Zon said.
Prabowo campaign spokesman Dahnil Azar Simanjuntak called on "all sides to hold back and not commit violence".
Police spokesman Dedi Prasetyo said that security forces on the ground, including military personnel, were not armed with live bullets.
Indonesian authorities say 40,000 police and army personnel are on duty across Jakarta to maintain security.
Chief security minister Wiranto said the government would temporarily block certain social media functions to prevent inflammatory hoaxes and fake news.
Australian Associated Press