Up to 10,000 people in the West New Britain province of Papua New Guinea are threatened by a volcano spewing out ash, smoke and steam.
The local disaster management office says villages within a 20 kilometre radius of Mount Langila are reporting heavy ashfalls.
The office's director, Major Paul Kaliop, says an assessment team has set out on the day-long boat journey to the remote area.
"There's one or two Catholic-run mission stations and health centres, government stations also there. They are reporting receiving quite a considerable amount of ashfall."
Major Kaliop says there's no road to the Gloucester area, airstrips are all disused, and he's communicating with the assessment team through VHF two-way radio.
Mount Langila burst into life on Wednesday after a long period of relative quiet.