Mr Bashir said the government must swiftly disband the minority Ahmadiyah branch of Islam to protect mainstream Indonesian Muslims and prevent violent sectarian unrest."Ahmadiyah is an infidel organisation using the name of Islam, which aims to disrupt Islam,'' he told a press conference called to urge the government to act on the recommendation of an inter-departmental team to outlaw the sect.
"We urge the Indonesian government to immediately and officially ban and dissolve Ahmadiyah. We warn the government that any delay to do so will potentially create horizontal conflicts,'' he said.
He explained that by "horizontal conflicts'' he meant sectarian violence between mainstream Indonesian Muslims and Ahmadis, who number only about 200,000 in Indonesia.
Without a ban, people might take matters into their own hands, he said, a warning made all the more resonant after a mob attacked and razed an Ahmadiyah mosque last week.
"We never recommend any attacks or destruction but Muslims will fight each other if the government doesn't want to ban Ahmadiyah,'' said the cleric, who served almost 26 months in prison for conspiracy over the 2002 Bali bombings before being cleared and released.
Habib Rizieq Shihab, head of the militant Islamic Defenders Front, said his followers would not resort to violence but stood ready to help the government enforce a ban through dialogue.
"If the government issues the ban, we agreed to help the government to convince the Ahmadiyah followers to return to the real Islam through dialogue. We won't use any violent approach,'' he said.
The government has not indicated how it will respond to last month's recommendation from the Coordinating Body for Monitoring Religions and Beliefs - a panel set up during the Suharto dictatorship - to outlaw Ahmadiyah.
The sect, established in the country since the 1920s, believes Mohammed was not the final prophet, contradicting a central tenet of Islam.
Its plight has raised concerns among moderate Indonesians and human rights activists about religious tolerance in the country of some 230 million people, nearly 90 per cent of whom are Muslim.
Earlier today, hundreds of people rallied in central Jakarta in a show of support for religious freedom.
Representatives of the Ahmadiyah sect as well as Muslims and Christians gathered to urge the government to resist pressure from Islamic hardliners to ban the sect.
"We are here to show to Indonesia, to the world, that Indonesians love peace. To show that there are more Indonesians who love peace than those who don't,'' an organiser told the crowd.
The demonstrators carried banners reading Stop Religious Fascism and Stop Violence in the Name of Religion.