Authorities have heightened alert levels and evacuations have begun from homes closest to Mount Agung, which has not erupted in more than half a century.
The volcano is just 50 miles from the tourist resort of Kuta and 20 miles from the popular resort of Ubud.
It has been rumbling since August but the ground has shaken hundreds of times in the past two days.
Now, officials have banned anyone getting within five miles of the volcano’s summit.
“Even though seismicity is not as sharp as two days ago, as much as 480 seconds of tremors have occurred. The community must remain vigilant,” said Willem Rampangilei, the head of Indonesia’s National Disaster Mitigation Agency.
While the island’s airport remains open currently, officials are said to be closely monitoring the situation. “There is no cancellation or volcanic ash,” a spokesman said.
The last time Mount Agung erupted was in 1963, killing more than 1,000 people.
Kuta is a popular tourist resort among Australians.