The eruption on Kadovar Island, north of Australia, could become explosive and images show the large plume of ash and smoke engulfing the island and reaching a staggering 2.1km (1.3 miles) above sea level.
The Rabaul Volcanological Observatory said: “Due to the steepness of the island, landslides are possible, and together with the explosive nature of the magma, tsunamis may be generated.
“Due to the size of the island, any activity will impact the local population.”
The Darwin Volcanic Ash Centre in Australia said the 1,197ft volcano started erupting on Friday and between 50 and 60 per cent of the island has already been covered by lava.
Cheyne O’Brien, a forecaster at the Advisory Centre said: “It’s just a continuous emission of volcanic ash at the moment.”
The plumes of ash billowing into the sky do not pose a hazard for aviation, but Ms O’Brien said that all it would take is a change of wind direction to cause travel chaos in the area.
Councillor Tom Kelly, on nearby Koper island, said: “The island is in a critical situation. The clues are darker and increasing at an alarming rate.”
An estimated 500-600 people live on the island, and all residents have been evacuated with no loss of life, said the US-based charity Samaritan Aviation, which operates seaplanes to remote areas of PNG.
The charity added: “We do not have any details yet as to where all of the families have been evacuated to but hope to have further information in the near future. Your continued prayers for those displaced are appreciated.”
Chris Firth, a volcanologist at Macquarie University, Australia, said there are no confirmed records of a previous eruption of Kadovar, adding: “It’s hard to predict what might happen, as there’s nothing to compare it to.”
Kadovar is a two kilometers wide volcanic island which is part of the Schouten Islands just off the coast of Papua New Guinea.