Indonesia's Mount Lewotobi Laki Laki volcano continued to spew towering columns of hot ash high into the air on Friday following the huge eruption that killed nine people and injured dozens of others.

Activity at the volcano on the remote island of Flores, in East Nusa Tenggara province, has increased since Monday's initial eruption, forcing the authorities on Thursday to expand the danger zone.

The latest activity has seen the largest column of ash so far recorded at 10 kilometres high, Hadi Wijaya, the head of the Centre for Volcanology and Geological Disaster Mitigation, told at a news conference.

Wijaya said volcanic materials, including smoldering rocks, lava and hot, thumb-size fragments of gravel and ash, were thrown up to 8 kilometres from the crater on Friday.

There were no casualties reported from the latest eruption.

The volcano monitoring agency has increased Lewotobi Laki Laki's alert status to the highest level.

Wijaya said authorities on Thursday expanded the danger zone to a radius of 8 kilometres on the northwest and southwest of the mountain slope as hot clouds of ash “are currently spreading in all directions.”

“We are still evaluating how far the (danger zone) radius should be expanded,” he said.

The volcanic activity has damaged schools and thousands of houses and buildings, including convents, churches and a seminary on the majority-Catholic Island.

Experts at the scene have found craters from rocks falling from the eruptions up to 13 metres wide and 5 metres deep.

Authorities have warned the thousands of people who fled the area not to return home, as the government planned to evacuate about 16,000 residents out of the danger zone.

The series of eruptions this week have already affected more than 10,000 people in 10 villages, with more than half moving into makeshift emergency shelters.

A total of 2,384 houses and public facilities were damaged and collapsed after tons of volcanic materials hit the buildings and destroyed a main road connecting East Flores district where the mountain is located to neighbouring Larantuka district, said Kanesius Didimus, head of a local disaster management agency.

Rescue workers, police and soldiers on Friday continued to search devastated areas to ensure all residents had been moved out from the danger zone, as logistic and relief supplies were provided to nearly 6,000 displaced people in three evacuation sites.

The National Disaster Management Agency has said residents of the hardest-hit villages would be relocated within six months, with each family waiting to be rehoused set to receive compensation of 500,000 Rupiah (USD 32) per month.

Three other airports in neighbouring districts of Ende, Larantuka and Bajawa have been closed since Monday after Indonesia's Air Navigation issued a safety warning due to volcanic ash.

Lewotobi Laki Laki is one of a pair of strato-volcanoes in the East Flores district of East Nusa Tenggara province, known locally as the husband-and-wife mountains. “Laki laki” means man, while its mate is Lewotobi Perempuan, or woman.

The 1,584-metre volcano is one of the 120 active volcanoes in Indonesia, an archipelago of 280 million people. The country is prone to earthquakes, landslides and volcanic activity because it sits along the “Ring of Fire,” a horseshoe-shaped series of seismic fault lines around the Pacific Ocean.