Jakarta – Unidentified gangs on Friday attempted to set fire to houses in troubled Poso, Central Sulawesi province, where 13 people have died this month in a fresh outbreak of well-planned violence, police officials said.

Brigadier General Sunarko, spokesman for the national police, said the attack occurred early Friday morning in the town, 1,575 kilometres northeast of Jakarta.

The arsonists managed to set fire to a small hut used for wood processing and broke the windows of a nearly house, where kerosene was tossed in but failed to catch on fire, Sunarko told the Elshinta private radio station.

The incident caused no injuries. The perpetrators fled the scene before police arrived to arrest them.

Local police authorities have not yet determined whether Friday's pre-dawn incident was connected with recent violence in Poso, said Sunarko, who added an investigation was still underway.

An unidentified group of gunmen launched two pre-dawn raids on Christian-dominated villages in the Poso district on October 10 and October 12, leaving at least 13 people dead and dozens of others injured.

On Thursday, top security minister Susilo Bambang Yudhoyono said combat troops would be put on offensive in Central Sulawesi province to crush what he called the "security disturbance movement" in the area.

Poso and nearby areas experienced communal clashes between Moslem and Christian communities between 2000 to 2001 that claimed more than 1,000 lives.

Authorities have yet to identify the perpetrators of the recent attacks, but government officials claimed they were "well-trained", consisting of outsiders and jointly working with local residents.