Hundreds of people have rioted in Indonesia after three Christians were executed for their part in sectarian violence six years ago. At least four people were injured, as mobs looted shops and attacked government buildings.

The three Christians were killed by police firing squads early Friday morning in the central Indonesian province of Sulawesi.

Fabianus Tibo, Marinus Riwu and Dominggus da Silva were found guilty of leading a Christian mob in clashes with Muslims in 2000 in the Poso area of central Sulawsi.

News of the executions sparked violent protests in Sulawesi, where cars and police posts were torched.

In eastern Indonesia, near the executed men's hometowns, mobs of angry Christians with machetes attacked government buildings. The rioters destroyed a jail, setting at least 190 prisoners free.

Government officials and community leaders have called for calm.

Rinaldy Damanik is the chairman of the Central Sulawesi Assembly of Churches. He says most people in Poso have returned home, but anger over the executions remains. He says, the rioters felt the trials of the three men were unfair, and the executions were unjust. He says Christians are angry because they have been asking for an independent investigation of the case, but have not received any response from the Indonesian government.

The three farmers were executed for their roles in the sectarian violence that plagued Sulawesi from 1998 to 2002. More than 1,000 people, both Christians and Muslims, died in the clashes, which diminished after the two sides signed a peace accord.

But Damanik says achieving a lasting peace between Christians and Muslims in Sulawesi will take time. He says, it will require a long process of healing and justice before the two communities will be able to move beyond the violent past. He says, the recovery process will be blocked, as long as questions remain over why these three Christians had to die.

Human rights organizations had urged Indonesia not to proceed with the executions, saying there were irregularities in the trials.

The three men had been scheduled to die last month, but their executions were postponed, after thousands of Indonesians protested and the pope appealed for clemency.

Indonesia has the world's largest Muslim population, but, in Sulawesi and some other eastern regions, the Christian and Muslim populations are roughly equal.