Droves of protesters, including women in headscarves, arrived in buses, motorcycles and even on foot from as far as Bali and Kalimantan, choking major roads in the capital city.
Men in white Islamic robes chanted “Allahu Akbar” (God is Greater) as they walked towards the mosque, carrying Indonesian flags and waving posters with the words “Arrest or Expel Ahok”, referring to the Jakarta governor.
Footage from local TV stations showed demonstrators standing on trucks and shouting through loudspeakers, calling for a peaceful rally. Police formed human barricades outside key buildings such as ministries, the National Monument and the presidential palace. Armoured vehicles were also on guard to prepare for any violence.
“It’s not a choice, but a duty to be here. We are not anti-ethnic. We just want legal action because blasphemy has been committed. This is Indonesia, we want to protect our diversity, not to hurt it,” a female protester called Becky told TVOne station.
Despite several road closures and diversions in the city centre, traffic was smooth elsewhere in Jakarta. Some businesses had told employees to work from home and a number of foreign embassies had also warned their citizens to stay away from the protests, citing fears that violence might erupt during the rally on Friday afternoon.
Protesters had gathered in the area since Thursday night, said Mr Eko, a security guard who works near the Gambir train station. “More arrived at about 2am to 3am, sitting around taking naps or just sharing food, they were peaceful. I hope they don’t start any trouble,” he said.
Organisers said 200,000 people, including many from outside Jakarta, will participate in the rally. They will march to the state palace to press for the authorities to charge Mr Basuki, better known as Ahok, for allegedly insulting Islam.
Despite the major rally, the governor who is seeking re-election, remains unfazed, saying he will continue to campaign on Friday.
“We believe the authorities can handle the rally and bear in mind that the participants have been told not to be violent when expressing their aspirations,” his campaign team spokesman Bestari Barus was quoted as saying by The Jakarta Post.
More than half of 100 eligible voters in the Jakarta gubernatorial election polled by The Straits Times this week said they plan to vote for Ahok.
The protest was sparked after Ahok, an ethnic Chinese and minority Christian, criticised opponents who cited a Quranic verse to attack him ahead of the gubernatorial election in February. He had told Muslim constituents last month not to be deceived by his opponents who used the reference to discourage them from voting for non-Muslim leaders. He had since apologised and clarified that he had no intention to insult Islam or the Quran.
Police believe the demonstrators on Friday will include local sympathisers of the Islamic State in Iraq and Syria (ISIS) from domestic militant groups, such as Jemaah Ansharut Tauhid and Jemaah Ansharut Daulah, but do not expect them to commit violence.
The rally, the second against the governor, has put the Indonesian capital on high alert, with about 20,000 police officers and at least 500 soldiers deployed in the city to prevent possible outbreak of violence.
Besides key landmarks and buildings in the city, authorities have also stepped up security at the domestic terminal at the Soekarno-Hatta International Airport.
President Joko Widodo has called for a peaceful rally and urged religious leaders and scholars in the country to unite against violence.
Known for his no-nonsense leadership style, Ahok has been the target of racism by Muslim hardliners, but he has also enjoyed strong support from Jakarta residents who widely see him as a clean and capable leader. He has effectively tidied up the city, relocated squatters, and rooted out incompetent civil servants.
Police have said they would continue to investigate the allegation of blasphemy, which is a criminal offence in Indonesia and carries a penalty of up to five years in jail.