Churches in Indonesia have appealed for calm amid protests that broke out following the execution of three Christian men in the country's Sulawesi province on Friday.

Hundreds of Christians have rioted in the region known for its interreligious violence despite calls for "forgiveness" rather than revenge from the son of the one of the dead men.

Cars have been torched and Muslims shops have been looted, while other reports state that 200 inmates have escaped after protestors attacked a prison in West Timor and invaded the state prosecutor's office.

Amid the violence, however, there were ongoing peaceful vigils to remember the men.

In Palu, 1,000 mourners squeezed into a local church to take part in a vigil to remember Fabianus Tibo, 60, Marinus Riwu, 48, and Domingus da Silva, 42 who were executed after being found guilty in 2000 of masterminding an attack on a Muslim boarding school which left 70 people dead.

During the vigil, Tibo's son appealed for forgiveness in memory of his father.

"My father begged us not to be angry, not to seek revenge. He asked to forgive those who did this to him. 'God blesses all of us,' he said."

The execution of the men came despite international appeals for the sentences to be overturned, including an intervention by Pope Benedict XVI.

Kate Allen, of Amnesty International, condemned the Indonesian government's decision to carry out the death sentence. "The executions of these men are a backwards step," she said.

"Such state-sanctioned killing is all the more unacceptable where there have been doubts about the fairness of the trial."

Appealing for calm, Vice-President Jusuf Kalla rejected suggestions that the executions were religiously or politically motivated. "We are concerned that the public misunderstood," he told reporters. "The case is not a religious or ethnic issue but simply a legal one."