Airlines pluck thousands of tourists from Bali

Airlines are flying thousands of stranded customers from Bali as a change in the wind blows volcanic ash away from the airport, the island's main international gateway. About 120,000 tourists have sat stranded after a surge in activity from Mount Agung that began last week grounded hundreds of flights.

Just 23 flights left Wednesday, and the airport continues to operate below its capacity of 400 per day. Still, more than 4,500 people have flown from Bali's airport, authorities say, with about 3,200 of them on international flights.

Read more: Why an eruption of Bali's Mount Agung is so dangerous

However, the airport on nearby Lombok island — also a popular tourist destination — closed again Thursday after ash and smoke drifted in its direction, making runways slippery and posing a risk to engines, which could suck particles in.

The shifting wind occurred as a result of the Cempaka cyclone, which has battered Indonesia's main island, Java. The cyclone has left at least 19 people dead in severe flooding and landslides.

Just a prelude?

The 3,031-meter (10,002-foot) Agung has already experienced a series of miniebullitions, and its crater continues to glow. Scientists warn that a major eruption could still happen at any moment.

Agung, which killed more than 1,100 people when it last erupted in 1963, began rumbling anew in September, forcing 140,000 residents to evacuate. Many returned to their homes when activity decreased in October. On Saturday, Agung belched smoke for the second time in a week in what volcanologists call a phreatic eruption, caused by the heating and expansion of groundwater.

Lava flows — which often precede the flaming floods of popular imagination — have also appeared. A worst-case scenario would involve an explosive eruption that causes the mountain's cone to collapse.

Read more: Ring of Fire: Five facts about the most earthquake-prone region in the world

About 43,000 residents have fled during the current flare-up. Though some residents have refused to leave the danger zone, which has a radius of 10-kilometers (6 miles), tens of thousands of people — some with respiratory problems linked to the volcanic ash — have filled up 225 evacuation centers. As many as 100,000 will likely need to evacuate in the case of a full eruption, disaster agency officials say.

Indonesia lies in the Pacific Ocean's Ring of Fire, where tectonic plates collide, causing frequent seismic activity. With 127 volcanoes, Indonesia is the world's most volcanically volatile country.

Last year, seven people died after Mount Sinabung, on Indonesia's western island of Sumatra, erupted.

mkg/ls (Reuters, AFP, dpa, AP)