JAKARTA, Indonesia  —  Unidentified assailants attacked a group of high school girls on Saturday in Indonesia's tense province of Central Sulawesi, beheading three and seriously wounding a fourth, police said.

The students from a private Christian high school were ambushed while walking through a cocoa plantation in Poso Kota (search) subdistrict on their way to class, police Maj. Riky Naldo said. The rural area is close to the provincial capital of Poso, about 1,000 miles northeast of the Indonesian capital Jakarta.

A file photo of a Christian girl after being beheaded in Indonesia.

He said the heads of the three dead girls were found several miles from their bodies.

Indonesia is the world's most populous Muslim nation. But Central Sulawesi has a roughly equal number of Muslims and Christians. The province on Sulawesi island was the scene of a bloody sectarian war in 2001-2002 that killed around 1,000 people from both communities.

At the time, beheadings, burnings and other atrocities were common.

A government-mediated truce ended the conflict in early 2002 but since then, there have been a series of bomb attacks and assassinations targeting Christians. A market attack in the predominantly Christian town of Poso killed 22 people in May.

A suspected Islamic militant told judges Wednesday he took part in the beheadings of three Christian girls on an Indonesian island wracked by sectarian violence because he wanted to avenge the deaths of Muslims. 

Hasanuddin told the Central Jakarta District Court he and two other men were "involved" in the October 2005 attack on the girls as they walked to school on Sulawesi island, the scene of interfaith battles that left at least 1,000 people dead from 1998 to 2002. 

"I was indeed involved in the beheadings," Hasanuddin, who like many Indonesians goes by only one name, told the court. "But we did it because authorities did nothing against massacres of Muslims."