The Islamic Defenders Front is demanding the arrest of Jakarta's Christian governor

Indonesian authorities said Monday they believe a protest planned by Muslim hardliners next month in the capital may be a guise for treason and are warning the organisers against holding the rally.

The protest planned for December 2 is to demand the arrest of Jakarta’s minority-Chinese governor, Basuki ‘Ahok’ Tjahaja Purnama who is being investigated for alleged blasphemy after he spoke about a passage in the Koran that prohibits Muslims from electing non-Muslims as leaders.

National police chief Gen Tito Karnavian and military chief Gen Gatot Nurmantyo said at a joint news conference they have received credible information about the possibility of treason behind the planned rally.

“We know that they have held several meetings where they plan to mobilise people to occupy the Parliament building,” Karnavian said.

The Parliament building was occupied by thousands of students during the mass protests in 1998 that caused dictator Suharto to step down.

Karnavian said an attempt to try to occupy the building again could be seen as a move to topple President Joko ‘Jokowi’ Widodo’s administration.

Ahok is a Jokowi ally and the accusation of blasphemy against the governor has galvanised their political opponents and given a notorious group of hard-liners a national stage.

The Islamic Defenders Front, a vigilante group that wants to impose Shariah law in the secular nation, is demanding Ahok’s arrest after a video circulated online of his remarks.

Nurmantyo reminded that while people have the right to protest, “if turns to be treason, then it will be the task of police and army to deal with.”

“Those who try to destroy this state are not religious persons,” Nurmantyo said. “I am sure that, and they would be dealing with the Indonesian military and police along with all Indonesian communities.”

At an earlier protest against Ahok, one person was killed and dozens were injured as police fired tear gas canister to disperse the crowd.

Ahok is first Christian governor of Jakarta in half a century. He has said he will run for a second term in February.