The 72-year-old cleric is accused of seven counts of terrorism related to a paramilitary training camp that was discovered last February in Aceh province, court official Supriyantorro said.
Hundreds of Bashir's supporters were expected to rally outside the trial, which gets under way as Indonesia tries to contain a spate of religious violence that has left three people dead and several churches badly damaged.
“Around 1,200 police officers have been readied to go to South Jakarta,“ police spokesman Boy Rafli Amar said, referring to the district court in the capital where the trial was set to take place.
“We hope their presence will provide a guarantee for the judges to conduct the trial as best as possible. We hope their presence can deal with whatever situation that might arise, inside or outside the court.“
Bashir's charges include “mobilizing people for acts of terror,“ which carries the death penalty, and financing Islamist militants. Police have said the group was training to carry out Mumbai-style attacks on Western targets and political figures in Jakarta.
It is the third time the cleric has faced terror-related charges since 2002, but police have failed to make any of the allegations stick. He served almost 26 months for conspiracy over the 2002 bombings of tourist nightspots in Bali that killed more than 200 people, before being cleared and released in 2006.