KOKOPO: Papua New Guinea`s volatile Ulawun volcano designated one of the world`s most hazardous erupted on Wednesday, spewing lava high in the air and sending residents fleeing.

A pilot for Niugini Helicopters flying near the crater witnessed a column of lava spurting vertically into the equatorial sky, along with ash that has been belching since early morning.

Ulawun, on the remote Bismarck Archipelago chain, is listed as one of 16 `Decade Volcanoes` targeted for research because they pose a significant risk of large, violent eruptions.

Witnesses said lava had cut off the main highway in north of the island.

`The volcanic activity at Mt Ulawun began at 7am this morning af ter slight rumbling and light emission,` Leo Porikura, an of ficial with the West New Britain DisasterOf fice, said earlier.

`The Rabaul Volcano Observatory has declared a stage one alert warning of a possible eruption.` Witnesses had reported ash spewing out of the 2,334 metre (7,657 foot) summit, sending trails spanning high overhead.

`The sky has turned black,` said Kingsly Quou, manager of the nearby Mayo Estates palm plantation.

Quou said that villagers living at the base of the volcano had already been evacuated and he and his colleagues were gathering their belongings.

Japanese satellite imagery and sources on the ground had shown sulphur dioxide and now volcanic ash drifting from the crater.

Australia`s Bureau of Meteorology said the ash reached more than 13 kilometres (44,000 feet) into the air.-AFP