(CNN) -- An earthquake that struck rural Indonesia left at least four people dead, authorities said Sunday.
At least seven others were injured, according to the National Disaster Management Agency.
The 6.6-magnitude hit Saturday near the city of Palu on the island of Sulawesi, the U.S. Geological Survey said.
Three of the hardest-hit districts are still unreachable because landslides triggered by the quake are blocking the roads. Heavy equipment and bulldozers are helping clear the roads.
Disaster, health and social welfare officials, including the Red Cross, are headed to the area to provide emergency assistance, trucks and ambulances.
Indonesia is on the so-called Ring of Fire, an arc of fault lines circling the Pacific Basin that is prone to frequent earthquakes and volcanic eruptions.
CNN's Kathy Quiano contributed to this report.