A dormant volcano on Kadovar Island has erupted spewing lava for the first time in known history. The volcano, which is on the northeast of Papua New Guinea, has sat dormant ever since its discovery by a Spanish navigator in 1545.

The Rabaul Volcanological Observatory has warned that the eruption could become explosive and bring landslides and tsunamis to the region, the New Zealand Herald reported.

It said: "Due to the steepness of the island, landslides are possible and together with the explosive nature of the magma, tsunamis may be generated.

"It appears from satellite imagery and aerial photographs that it started with mild vulcanian activity from a vent at the southeast base.

"It appears a fissure may be opening just inside of the western wall of the net's breach descending dow to at least sea level."

After flying over the island, Wewak District Administrator Ricky Wobar said on social media: "The situation is very critical."

Three years ago, the volcano had experienced a "seismic unrest", but is not believed to have erupted before, the Daily Star reported.

According to experts, it is the "first surprise volcano to erupt in 2018".

Authorities were alerted after distressed residents called them for help. As much as 50 to 60% of the island is said to be covered by the lava since the eruption, forcing at least 600 residents to evacuate.

The eruption has also caused a thick layer of dust, clouds and smoke, and neighbouring islands have been showered with ashes, News.com.au reported.

The neighbouring island of Kopar raced to help the remaining residents evacuate. Kopar councilor Tom Kelly said "the clouds are darker and increasing at an alarming rate".