The first eruption took place at 11.04am local time and lasted nearly 11 minutes, according to a statement from the Indonesian volcanology agency.
The second was at 2.41pm and lasted a little over 10 minutes, spewing volcanic material 900m above the crater.
"Residents and visitors around Mount Lewotobi Laki Laki are prohibited from conducting any activity within the 3km radius from the centre of eruption," the agency said.
The mountain, located on the popular tourist destination of Flores island, had several major eruptions in January, prompting authorities at the time to raise the alert status to the highest level and evacuate at least 2,000 residents.
The volcano is currently at the second highest alert level.
Indonesia, a vast archipelago nation, experiences frequent eruptions due to its position on the Pacific Ring of Fire, an area of intense volcanic and seismic activity.
In December last year, an eruption at one of the country's most active volcanoes, Mount Marapi in West Sumatra, killed at least 24 climbers, most of them university students.
And in May, more than 60 people died after heavy rains washed volcanic material from Marapi into residential areas, sweeping away homes.
AFP
Lady Karma has landed for 6 months.
Get Spiritual.