75,000 flee Bali

Vehicles laden with food, facemasks and bedding have been sent to help more than 75,000 people who have fled a volcano on the tourist island of Bali, as the Indonesian president flew in to visit crowded aid centres.

Mount Agung, 75 kilometres from the resort hub of Kuta, has been rumbling since August and threatening to erupt for the first time since 1963 -- a potential blow to the country's lucrative tourism industry.

Increasingly frequent tremors show the molten magma is still rising towards the surface, with the mountain entering a "critical phase", said the national disaster mitigation agency.

Around 62,000 people lived in the danger zone before the evacuations, according to the agency, but residents just outside the area have also left as a precaution.

The Indonesian Center for Volcanology and Geological Hazard Mitigation said there has been an increase in volcanic tremors, with a total of 564 recorded Monday.

Speaking in Klungkung district, President Joko Widodo told evacuees the government would do its best to reduce economic losses incurred during the evacuation.