Almost 3,000 people were evacuated from the Palue Island in the East Nusa Tenggara province early Saturday after Mount Rokatenda erupted shooting ash and smoke about a mile into the air, local officials told AP.
Among the six dead were two children whose remains have not been found yet, a National Disaster Mitigation Agency official told the agency.
Video footage on Indonesian television showed giant clouds of smoke rising from the volcano after an eruption that lasted about seven minutes.
Mount Rokatenda is one of about 129 active volcanoes in Indonesia, an archipelago of more than 17,000 islands that's home to some 240 million people, AP said.
The country is prone to earthquakes and volcanic activity because it sits along the Pacific "Ring of Fire," a horseshoe-shaped series of fault lines, it said.