Central Sulawesi is a remote and backward province of Indonesia wedged between the predominantly Christian north of Sulawesi island and the mainly Muslim south.
Its people earn a living from farming and fishing; the province gets little investment and contributes little to the national economy.
After a period of relative calm, violence again broke out in November 2001.
Some claimed the violence was a spill-over from the fighting between Christian and Muslim communities in the Moluccan islands to the east.
Others believe it was a consequence of the influx of mainly Muslim migrants from Java to this under-populated region, which has reduced the Christian majority and thus their powerful position.
'Black magic'
Muslims now dominate political and commercial life in the area around Poso where the violence first erupted.
It was a drunken brawl between Christian and Muslim youths that sparked the violence in December 1998 - leaving hundreds dead and thousands homeless. Unfounded rumours that churches had been burned added to the chaotic atmosphere and exacerbated the violence.
There were claims too that black magic was being invoked in this very traditional region. Many of those killed had been abducted from their homes and their decapitated bodies were later fished out of the Poso River.
By the time the violence subsided many months later, an estimated 1,000 people had been killed. Tens of thousands of mainly Christians inhabitants had been expelled from Poso and surrounding villages.
Poso itself lay in ruins. A strengthened military garrison maintained an uneasy peace.
'Intimidation'
Now the violence has broken out again, with at least 100 people killed in the Poso area during the Muslim fasting month that ended in mid-December.
Christians say the new violence was caused by the arrival in Poso of the Laskar Jihad, or Holy Warriors, a Java-based organisation which claims to offer protection for Muslims it says are being besieged by other communities.
In 2000 Laskar Jihad was blamed for escalating Muslim-Christian violence in Ambon, the Moluccan capital.
In Poso, a rival paramilitary organisation, the Christian Red Force, emerged to retaliate against what Christians say are attempts to intimidate them into leaving their homes.
Both militant groups are armed with traditional spears, bows and arrows and slings as well as homemade firearms and bombs.
A series of tit-for-tat raids in villages south of Poso in November left at least 12 people dead and caused an exodus of Christians southwards to the town of Tentena on Lake Poso.
As many as 50,000 refugees were reported to have arrived in the town, a vast number in this sparsely populated and remote region.
Religious festivals
Muslims had threatened to occupy Tentena before Eid al-Fitr, the feast in mid-December which marks the end of the fasting month.
In the end, no violence was reported, but the closeness of Ramadan and Christmas may have contributed to the heightened communal tension.
Muslims have accused Christians of failing to respect the fasting month. Three years ago the first violence broke out when the start of the Muslim fasting month coincided with Christmas.
Poso's remoteness has made it difficult for the authorities to quell the violence. The provincial capital, Palu, is four hours away by road. Poso has no airport and no local newspapers, a factor blamed for the rapid spread of rumours.
But Jakarta has stepped up security and there are signs the government may be prepared to clamp down on armed groups from outside the province, like the Laskar Jihad.
President Megawati Sukarnoputri, who represents a nationalist rather than an Islamic political party, is already walking a tightrope. She has publicly supported US President George Bush in his anti-terror campaign, but under pressure from Muslim groups, she criticised the bombing of Muslim Afghanistan.
The war in Afghanistan has led to an increased militancy amongst some Indonesian Muslims, who feel they have lost power with the accession of Mrs Megawati.