CANBERRA — Authorities in Papua New Guinea are removing thousands of people at risk of a volcanic eruption in the South Pacific Island nation’s north, the government said Monday.

In the Philippines, nearly 15,000 people fled from villages around that country’s most active volcano Monday, as lava flowed down its crater in a gentle eruption that scientists warned could turn explosive.

Peter O’Neill, the prime minister of Papua New Guinea, said he had directed all relevant state resources be made available to support the evacuation of people at risk due to volcanic eruptions on Kadovar Island in the East Sepik region.

He also warned northern coastal communities to be alert for possible tsunamis.

‘‘Volcanoes are very unpredictable,’’ O’Neill said. “We are hearing various reports that activity has been building up and we need to take all precautions to keep our people safe.’’

Australian Broadcasting Corp. reported 3,000 people were being evacuated from Biem Island, where 700 were evacuated in the past week.

Papua New Guinea sits on the ‘‘Pacific Ring of Fire’’ and has frequent volcanic eruptions. The Philippine Institute of Volcanology and Seismology increased the alert level for the Mount Mayon volcano to three on a scale of five, indicating an increased prospect of a hazardous eruption ‘‘within weeks or even days.’’

ASSOCIATED PRESS