JAKARTA - Around 100,000 people live on the slopes of Mount Agung in Bali, but only 40,000 people have left their homes to reach safer areas, said Indonesia's disaster agency on Tuesday (Nov 28).
The authorities have to forcibly evacuate around 60,000 people, along with thousands of cattle, from the slopes of Mount Agung, reported local media.
"There are residents who don't want to leave their villages because they said the situation is still safe and they are considering the life of their cattle," said Mr Sutopo Nugroho, a spokesman for the National Disaster Mitigation Agency (BNPB).
According to Sutopo, 8,543 cattle have been evacuated to 43 safe zones, though around 5,500 remain in harm's way, reported Jakarta Globe.
Many villagers have refused to evacuate their homes without their cattle, a main source of livelihood in rural eastern Bali.
"Not all people in the danger zone are prepared to take refuge," he said, adding that just over 29,000 people were registered at the 200 evacuation centres.
"There are still a lot of residents staying in their homes.
"There are personnel doing the sweeping, if they need to be forcibly evacuated," Sutopo told reporters.
Some villagers who fled their homes in September, when the alert was last raised to the highest level, have gone home after the alert was lowered.
On Monday (Nov 27), the Indonesian authorities raised the alert for the volcano to the maximum level and said 100,000 residents living near the volcano had been ordered to get out of an 10km no-go zone.
Mount Agung's last eruption in the 1963, one of the deadliest ever seen in a country with nearly 130 active volcanoes, killed around 1,600 people.
"I am very worried because I have experienced this before," 67-year-old evacuee Dewa Gede Subagia, who was a teenager when Agung last roared, told AFP.
"I hope this time I won't have to evacuate for too long. In 1963, I left for four months."
Experts said that Mount Agung's recent activity matches the build-up to the earlier disaster, which ejected enough debris - about a billion tonnes - to lower global average temperatures by 0.2 to 0.3 deg C for about a year.
The volcanic eruption has also affected flights to and from the island.
Airnav Indonesia, the country's air navigation agency, suspended operations at I Gusti Ngurah Rai International Airport in Denpasar for a second straight day on Tuesday, causing the cancellation of more than 400 domestic and international flights.
Mr Sutopo said the government has prepared two trillion rupiah (S$178 million) in relief funds.
Indonesia's Volcanology and Geological Disaster Mitigation Centre has warned that an eruption of the same intensity as the 1963 eruption could send rocks bigger than a fist flying a distance of up to 8km, and volcanic gas a distance of 10km within three minutes.
Indonesia is the world's most active volcanic region. The archipelago nation with over 17,000 islands lies on the Pacific "Ring of Fire" where tectonic plates collide, causing frequent volcanic and seismic activities.
Last year, seven people were killed after Mount Sinabung on the western island of Sumatra erupted. A 2014 eruption at Sinabung killed 16.