Madang Provincial Disaster office says it is arranging for fresh water to be taken to the villages of eruption plagued Manam Island.
Provincial Disaster Coordinator Rudolf Mungali says priority is clean drinking water as there are no sources of clean water left..
He says the medical teams sent to the island have warned officials to expect an outbreak of dysentery.
Mungali says measures are being taken to prevent dysentery and other diseases that might be caused by the eruption.
He says no serious injuries were reported.
Over seven villages are covered in ash and small volcanic stones after Manam volcano erupted on Friday.
This has destroyed their food gardens and sources of drinking water in tanks and wells.
The volcano has quietened down but is still blowing out smoke.
Mungali says they are monitoring activities through the Rabaul Volcano Observatory.