Farouk Arnaz & Shesar Andriawan – Thousands of members of the hard-line Islamic Defenders Front (FPI) paraded through the streets of Jakarta on Sunday in commemoration of the group's 15th anniversary.

Sporting their trademark all-white attire, the group kicked off its celebration by riding in vehicle convoys through the West Jakarta neighborhoods of Slipi and Petamburan.

Munarman, a spokesman for the group, said that around 5,000 people were expected to participate in the day-long celebration, which began Sunday at 10 a.m.

"This is how the FPI celebrates every anniversary," he said. "God willing, we will conduct the rally in an orderly fashion. There is nothing to be worried about."

The group's route will take it from its headquarters in West Jakarta through Central and East Jakarta.

Speaking at the beginning of the gathering, FPI chief Rizieq Syihab urged members to behave themselves during the rally and not be easily provoked by outsiders.

National Police Chief Gen. Timur Pradopo said that the FPI must celebrate its anniversary peacefully. "[It] must not disturb other people," he said on Friday.

Hundreds of officers from the National Police and the Jakarta Police have been deployed to help maintain order and direct traffic away from the rally throughout the day.

Indonesian news portal detik.com, meanwhile, reported that vehicles heading from Tanah Abang to Slipi were stuck in gridlock because of the mass gathering.