JAKARTA (JAKARTA POST/ASIA NEWS NETWORK) - The uproar over the burning of the flag of a hardline Islamist group by members of Indonesia's largest Muslim organisation threatened to boil over as thousands of conservative Muslims demanded that those responsible be taken to task.

In the two-minute clip that went viral last week, people wearing uniforms of a civilian security unit under Banser, the youth wing of Indonesia's largest Muslim organisation, Nahdlatul Ulama (NU), are seen setting ablaze a black flag bearing the Islamic shahada text of Hizbut Tahrir Indonesia (HTI).

HTI is a banned Islamist group that calls for the establishment of a caliphate ruled by syariah law. Shahada is an Islamic creed and the declaration of the belief that Allah is the one and only God and that Prophet Muhammad is God's messenger.

In the video, dozens of other people in the same uniform are seen watching over the burning. When the fire engulfs the flag, members start singing the Banser marching song.

The incident occurred during a National Santri Day rally in Garut, West Java, last Monday. The Banser members had seized the flag after it was raised by a man.

Indonesian netizens were outraged by the video, saying the flag-burning was a blasphemous act.

Islamic groups took to the streets last Friday (Oct 26), calling the government and law enforcers to take legal action against the Banser members who burned the flag.

The protesters, who staged a rally in front of the office of Coordinating Political, Legal and Security Affairs Minister Wiranto, carried the black and white flag and chanted the Islamic creed, while decrying the burning, calling it unacceptable and an insult to all Muslims.

Mr Yusuf Martak, the chairman of the National Movement to Safeguard Fatwas (GNPF), which participated in the protest, said before the crowd of protesters that Banser's action had divided the Muslim community.

"If the government doesn't want to appear as anti-Islam or doesn't take sides with ulemas, please prove that (the flag-burning) was wrong and cannot be tolerated," Mr Yusuf said last Friday.

In the past few days, Muslim groups and Islamic authorities, including the Indonesian Ulema Council (MUI), have criticised Banser for the incident.

Banser has refused to apologise for the incident on the grounds that the flag belonged to the outlawed HTI, but the flag burners themselves did apologise, saying the incident was spontaneous and did not reflect their organisation's views.

The police questioned the three Banser members but have released them. The man who raised the HTI flag, Uus Sukmana, faces a possible sentence of three weeks in jail for disrupting a public gathering, according to Article 174 of the Criminal Code.

Mr Muchsin Alatas, an executive with the hardline Islam Defenders Front (FPI), demanded that the chairman of NU's youth wing, Mr Yaqut Cholil Qoumas, be prosecuted for the flag-burning incident. He also demanded that Mr Wiranto arrange a meeting among NU chairman Said Aqil Siradj, Mr Yaqut and Banser executives.

Mr Yusuf and Mr Muchsin, along with five other protesters, were received by Mr Wiranto's secretary, Lieutenant-General Agus Surya Bakti. Mr Wiranto was in Palu, Central Sulawesi, to discuss post-earthquake reconstruction with local administrations.

After the meeting,Lt-Gen Agus and the delegation representing the protesters addressed the crowd together. However, the participants of the rally expressed disappointment over Mr Wiranto's absence.

Thousands of Muslim groups from Surakarta, Central Java, also held a protest in Klaten, condemning the incident while carrying tauhid flags as they marched to the Klaten Police headquarters. They urged the police to punish the perpetrators.

The incident has sparked fears of sectarian strife in the country ahead of the 2019 presidential election.

Mr Hasanuddin Ali, a political analyst from the Alvara Research Centre, said the government had learnt a lesson from the blasphemy case which felled former Jakarta governor Basuki "Ahok" Tjahaja Purnama. Ahok was convicted of blasphemy followed a string of sectarian rallies that contributed to a divisive Jakarta gubernatorial election in 2017.

Although officials had acted swiftly to prevent the flag-burning incident from spiralling into a major security issue, the government still needed to intensify communications with the different groups that demanded prosecution, he said.

Concerns over hostility against Banser and Ansor had resulted in the cancellation of the groups' mass gathering of around 100,000 people in Yogyakarta last Friday.

Ansor secretary-general Abdul Rochman cited security reasons for the cancellation, saying that the group was concerned about unwanted brawls breaking out if the gathering had gone ahead.