A Muslim man has gone on trial in Jakarta over the beheading of three Christian schoolgirls in the Indonesian island of Sulawesi.
Hasanuddin was accused of planning the attack as revenge
Hasanuddin is the first of three suspects to face trial over the October 2005 killings, which shocked Indonesia.
All three men could be sentenced to death if found guilty.
The murders threatened to reignite violence between Sulawesi's Muslims and Christians, which has continued despite a 2002 peace deal.
Tensions have risen in recent weeks following the execution of three Christian militants in September, for attacks against Muslims in 2000.
Hasanuddin said nothing as he arrived in the packed courtroom, according to the BBC's correspondent in Jakarta, Lucy Williamson.
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
He faces charges of premeditated murder and carrying out acts of terrorism, she says.
Prosecutors accused him of masterminding the attack, though they said the actual perpetrators remained at large.
They said Hasanuddin, who had attended a militant training camp in the Southern Philippines, planned the attack as retaliation for the killing - by a Christian mob - of Muslims at a school in 2000.
Hasanuddin's lawyer, Achmad Michdan, told reporters outside the court that his client denied being the perpetrator and had merely been asked for advice, Reuters news agency reported.
The three schoolgirls were beheaded as they walked to the private Christian school near their home in the town of Poso, in central Sulawesi.
One of their heads was discovered outside a church, adding to the suspicion the murders were religiously motivated.
The trial is being held in Jakarta for security reasons.
Sulawesi has long been the scene of violent attacks between Christians and Muslims.
More than 1,000 people are believed to have been killed during two years of violence triggered by a brawl between Christian and Muslim gangs in December 1998.
Indonesia is the world's most populous Muslim nation, but Christianity is commonplace in some parts of Sulawesi.