Sunday night's eruption on the island of Flores in the province of East Nusa Tenggara, which damaged more than 2,000 houses, was followed by smaller eruptions on the next two days.
On Thursday, the volcano erupted again at 00:40 a.m., the volcanology agency said in a statement, with a second eruption two hours later emitting a fiery red column of lava.
Five eruptions of the volcano, 1,584-m (5,200-ft) tall, followed from 6 a.m. to 11 a.m., with the last belching out the 8,000 m (26,250 ft) column of ash.
Billows of the thick grey ash emerged from the crater in pictures provided by the agency, an official of which, Hadi Wijaya, said it was keeping the highest alert status for the volcano, which remains very active.
"We expect construction of the new houses will be completed within six months," the head of Indonesia's disaster agency, Suharyanto, told reporters, adding that the government was scouting for locations.
The agency is still calculating the number to be relocated. Evacuees lacked adequate water supplies, Suharyanto added.
About 5,816 of the more than 16,000 people living in areas nearest the volcano had been evacuated to other villages, said Heronimus Lamawuran, a spokesperson for the Flores regional government.
Indonesia sits on the "Pacific Ring of Fire", an area of high seismic activity atop various tectonic plates.
