JAKARTA • Indonesian President Joko Widodo called for calm yesterday amid simmering religious tension as helicopters dropped police leaflets over the capital, warning residents of the risk of harsh penalties if new rallies led by Islamists turn violent.

About 50,000 leaflets were dropped, warning residents not to disrupt public order or undertake "subversive" activities, which carry punishments including death or life in prison.

Police plan to deploy 18,000 officers for new protests, planned for today and next Friday, in the city of 10 million.

Jakarta Police chief Mochamad Iriawan has also issued an official warning against acts of treason and disturbance of public order during planned protests by Muslim groups against the capital's Christian and ethnic Chinese governor Basuki "Ahok" Tjahaja Purnama, the Jakarta Globe reported.

The warning letter, signed by the police chief on Monday, came after reports that some groups were attempting to "occupy" the Parliamentary Complex during a street protest planned for today, a move that police said they would consider an act of treason.

Mr Joko sought this week to reassure investors and show that his political coalition is united after more than 100,000 Muslims, led by hardline groups, took to the streets on Nov 4 to call for the ouster of Ahok, who has been accused of insulting the Quran.

One person was killed and more than 100 were wounded when the protest, the biggest in the city in recent years, briefly turned violent.

Indonesia has the world's largest Muslim population and is home to Christian and Hindu communities.

Mr Joko has met top political, security and religious figures since the Nov 4 rally, after accusing unidentified "political actors" of inflaming the tension.

Police last week named Ahok a suspect in the blasphemy probe. He faces up to five years in prison if found guilty.

One hardline group, the Islamic Defenders Front, said its members plan to march again next Friday but it pledged that the protest would be peaceful.

Ahok, who is running for re-election in February, is up against two Muslim rivals.

A poll published yesterday showed he has slipped to second place amid the blasphemy allegations. Rival Agus Yudhoyono, son of previous president Susilo Bambang Yudhoyono, is now in the lead, the poll showed.

REUTERS