A vulcanologist in Papua New Guinea is warning that volcanic ash from the Rabaul eruptions might turn into mud flows that could destroy villages.
Ima Itikarai, from the Rabaul Volcanological Observatory in East New Britain Province, says there has been a lot of ash since mid-June, and it is building up on the town, on the flanks of the hills and near Rabaul harbour.
He says if heavy rain fell the ash would be washed down the hills and surrounding area producing mudflows into low-lying areas.
The volcano erupted in 1994 destroyed much of Rabaul.
There have been periodic minor eruptions since then.