Fifteen Muslim men have been arrested in connection with a spate of attacks on the Indonesian island of Sulawesi in recent years, police say.
The attacks include the beheading of three Christian schoolgirls last year and the bombing of two markets in 2004.
Sporadic attacks between Sulawesi's Muslims and Christians have continued despite a peace deal signed four years ago that put an end to fighting.
There has been a surge in attacks in the province in recent weeks.
The men were arrested after an eight-month investigation, police said.
Another 29 suspects are still at large.
Previously known as Celebes, Sulawesi is Indonesia's fourth largest island
80% of residents are Muslim, while 17% are Christian
A December 1998 brawl in Poso led to months of religious violence in which hundreds died
They are suspected of being involved in 13 separate attacks between 2001 and 2006.
These include the beheading and mutilation of three teenage girls who were attacked on their way to school near the city of Poso, in eastern Sulawesi, in October 2005.
The recent rise in tension on Sulawesi has been attributed by many to the execution of three Christians in September for their role in the province's long-running conflict, the BBC's Lucy Williamson in Jakarta says.
But others say it is the heavy presence - and behaviour - of the security forces which is fuelling the unrest, she adds.
Indonesian Vice-President Yusuf Kalla is in the province this week to meet religious leaders and try and ease the tensions.