Armed gangs of indigenous Dayaks have broadened their campaign of terror in Borneo, forcing thousands to flee.
Dayak men, armed with spears and machetes and chanting "War, War!", hunted settlers from the island of Madura hiding in forests.
They also besieged about 15,000 refugees sheltering in camps and waiting for the Indonesian government to evacuate them.
The violence spread to Central Kalimantan's provincial capital Palangkaraya as Dayaks burned dozens of homes and businesses.
"The communal conflict could move to more remote areas that are difficult to reach," Indonesia's top security minister Susilo Bambang Yudhoyono said. "Action will be taken to prevent it spreading."
The Dayaks set up road blocks throughout the city, burning tyres and threatening motorists with homemade weapons.
Indonesia's outnumbered security forces, who have been condemned in the past week for doing too little to stop the bloodshed, are making little attempt to control the situation.
Yudhoyono reiterated that the campaign of ethnic cleansing would end within three days.
However, that did little to stop many Madurese who fled to Banjarmasin in the neighbouring Southern Kalimantan province.
Government officials said the body count from eight days of killings stands at 270 - nearly all Madurese.
However, they say the death toll could be as high as 1,000 as uncounted bodies lay rotting in houses and fields.