An Indonesian court has sentenced three Muslim militants to jail for beheading three Christian schoolgirls in Central Sulawesi in 2005.
Hasanuddin has admitted his involvement in the attacks
Hasanuddin, 34, was given 20 years for planning the attack, while two accomplices were given 14 years.
Hasanuddin had earlier told the court he helped plan the attack but rejected allegations he masterminded it.
The beheading of the girls, attacked as they walked to school in Poso in 2005, drew international condemnation.
It also fanned tensions in Sulawesi, where Muslim-Christian violence has continued despite a 2002 peace deal.
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
Hasanuddin's denial was rejected by chief judge Binsar Siregar, who said: "The accused was proven to plan and move other people to carry out terror acts."
The court in Jakarta was also told that Hasanuddin had left a message next to the severed heads of the girls, saying: "A life for a life. A head for a head".
A separate court sentenced defendants Irwanto Irano and Lilik Purwanto to 14 years each.
Speaking before his sentencing, Hasanuddin said going to jail did not concern him.
"It's not a problem (if I am being sentenced to prison) because this is a part of our struggle. What will become a problem is if our brothers decide to get revenge," he said.
The three girls were attacked as they walked to the private Christian school near their home in Poso. One of their heads was discovered outside a church.
The trial had been told that the attack was timed to take place during a festival at the end of the Muslim holy month of Ramadan.
Hasanuddin said he wanted to avenge the deaths of Muslims killed during previous religious violence in the country, the world's most populous Muslim nation.
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.
Tensions have risen in recent months following the execution of three Christian militants in September 2006, for attacks against Muslims in 2000.