Authorities were alerted after receiving calls for help from distressed residents.
At least 600 residents who lived on the island were forced to evacuate — some in a dingy — as authorities rushed to help the displaced.
The Rabaul Volcanological Observatory told Loop PNG the eruption could "become explosive".
"Due to the steepness of the island, landslides are possible and together with the explosive nature of the magma, tsunamis may be generated," a report read.
"IT appears from satellite imagery and aerial photographs that it started with mild vulcanian activity from a vent at the SE (southeast) base of the cumulodome".
"It appears a fissure may be opening just inside of the western wall of the vent's breach, descending down to at least sea level.
Wewak District Administrator Ricky Wobar said the situation on the island had "worsened" after flying overhead "to assess the situation on the island, where they observed lava coming out of the once dormant volcano".
"The situation is very critical," he said on social media.
Update on Kadovar Island!
We just returned from another flight to check on the current conditions on Kadovar. As you can...
Posted by Samaritan Aviation on Friday, 5 January 2018
Authorities sent boats from Kopar, Kadovar's nearest island neighbour, approximately half an hour away, to evacuate residents living on the island.
Fifty to sixty per cent of the island is covered by lava since the volcano began to erupt.
"The island is in a critical situation. The clouds are darker and increasing at an alarming rate," Kopar councillor Tom Kelly told Loop PNG.
Update for Kadovar Island!
We just returned from another flight to check on the current conditions of the volcano. Chris Bais from the ESP Governors office, Ricky Wobar the DA of the Wewak District and Samaritan pilot Tracy Hamer give a quick update. The reports we have is that all of the residents of the island have been evacuated and that their has not been any loss of life. We do not have any details yet as where all of the families have gone to and hope to have further information in the near future. Your continued prayers for those displaced are appreciated.
Posted by Samaritan Aviation on Saturday, 6 January 2018
While it is the first time believed to have erupted, a possible eruption was witnessed by early explorers in 1700. The volcano was quiet again until 1976 for a short period of heightened thermal activity and again in 2015 with a burst of "seismic unrest".
Prayers for Kadovar Island!
In the past 12hrs we received a call for help. A resident of the island told us that the...
Posted by Samaritan Aviation on Friday, 5 January 2018