Three Christian militants convicted of leading attacks that killed at least 70 Muslims six years ago were executed by firing squad Friday, sparking fresh sectarian violence in central and eastern Indonesia, officials and witnesses said.

Christian mobs torched cars and police posts in restive Sulawesi province. Elsewhere, security forces fired warning shots to disperse crowds who blockaded roads, looted Muslim-owned shops and burned a prison, freeing hundreds of inmates. Four people were reported injured.

On the island of Flores, the executed men's birthplace, machete-wielding mobs ran through the streets, sending women and children running in panic, police and witnesses said.

Indonesian Vice President Jusuf Kalla appealed for calm, saying the deaths of the Roman Catholic men had nothing to do with religion.

"It's a matter of law," he told reporters in the capital Jakarta. "If the people resent the law, we are doomed."

Fabianus Tibo, 60, Marinus Riwu, 48, and Dominggus da Silva, 42, were taken from their tightly guarded prison and executed at 1:45 a.m. local time (1745 GMT Thursday) on the southern outskirts of Palu, said I Wayan Pasek Suartha, a spokesman for the attorney general.

They were killed simultaneously by three, 12-member firing squads.

The men were found guilty of leading a Christian militia that launched a series of attacks in May 2000 — including a machete and gun assault on an Islamic school that left at least 70 men dead.

It was one of the most brutal attacks during sectarian violence that swept Sulawesi province from 1998 in 2002, killing more than 1,000 people from both faiths. A peace deal largely ended the bloodshed, though isolated attacks have continued.

The case against the men raised questions about the role of religion in handing down sentences — only a handful of Muslims were ever punished, and none were sentenced to more than 15 years in jail — and fresh debate about capital punishment.

CountryWatch: Indonesia

The European Union issued a statement calling on Indonesia — which is expected to soon kill three Islamic militants for the 2002 Bali bombings — to halt all executions.

The killings occurred despite an appeal last month by Pope Benedict XVI to spare the men. A Vatican spokesman, the Rev. Federico Lombardi, told the Italian news agency ANSA that news of the execution "was very sad and painful."

Palu, where the executions took place, was largely calm, with thousands of police standing on street corners and guarding markets and churches, watching as some 1,000 mourners packed the St. Maria's church early Friday to take part in a requiem.

"My father begged us not to be angry, not to seek revenge," Tibo's son, Robert, told Christian followers after the morning prayers. "He asked us to forgive those who did this to him. God blesses all of us, he said."

But violence flared in the Sulawesi villages of Tentena and Lage, where hundreds of Christians went on a rampage after learning of the deaths.

Thousands also rallied in the eastern province of East Nusatenggara, home to many Roman Catholics, blockading roads and setting a court, prosecutor's office and other government buildings on fire.

Some 200 prisoners escaped in the town of Atambua, and only 20 had been recaptured by mid-afternoon, deputy national police chief Lt. Gen. Adang Dorodjatun said, calling on the others to turn themselves in.

Though the government insists the Christian men got a fair trial in 2001, with 28 witnesses providing testimony, legal experts note that the country's judiciary is corrupt and susceptible to outside influence.

Human rights workers say that while it was possible the men took part in some of the violence, they almost certainly were not the masterminds. Others said crowds of Muslim hard-liners gathered at the court during the hearings, likely intimidating judges, prosecutors, defense attorneys and witnesses.

"The men's lawyers received death threats, including a bomb planted at one lawyer's house and demonstrators armed with stones outside the courthouse demanded that the three be sentenced to death," said Isabelle Cartron of London-based Amnesty International.

The men told relatives and a priest during final prayers at their jail Thursday that they were innocent but ready to die. They had said they hoped investigations into the clashes would continue, though the government says its probe is complete.

The bodies of Tibo and Riwu were placed on police helicopters and flown back to their village of Beteleme in Central Sulawesi's Morowalai district for burial, said police spokesman Lt. Col. Muhamad Kilat. Da Silva was buried overnight in Palu.

Indonesia is a secular nation with the world's largest number of Muslims, about 190 million. In Sulawesi and several other eastern regions, Christian and Muslim populations are roughly equal.

Many analysts have speculated that the timing of Friday's executions was linked to the upcoming executions of three Muslims convicted in the 2002 bombings on Bali island that killed 202 people.

They received delays in their executions last month and some analysts said the government did not want to risk public anger by executing the Bali bombers before the Christians. The government has denied this.