Officials warned residents and airplanes to stay away from part of Hawaii’s Big Island after an ash plume from within Kilauea volcano’s summit crater rose as high as 3.6km in the air.

The US Geological Survey issued a red alert Tuesday, stating a major eruption is imminent or underway, with ash potentially affecting air traffic.

It is the first time the alert has been issued since Kilauea began erupting again 12 days ago.

USGS spokeswoman Michelle Coombs said the situation was “very hazardous for aviation”. It is unknown what caused the intensifying ash emissions.

The red alert comes as the Hawaiian Volcano Observatory (HVO) warned the eruption could become more violent.

Lava flows down a Hawaiian street. Photo: AAP

“We’re observing more or less continuous emission of ash now with intermittent, more energetic ash bursts or plumes,” Hawaiian Volcano Observatory (HVO) Deputy Scientist-In-Charge Steve Brantley told reporters.

“At any time, activity may become more explosive, increasing the intensity of ash production and producing ballistic projectiles near the vent,” the HVO said later in a statement.

While ash is not poisonous, it can cause irritation to the nose, eyes, and airways, causing “choking and inability to breathe,” the HVO said.

Ash has been wafting continuously from a vent in the crater, Halemaumau, and drifting southwest, causing ashfall and volcanic air pollution to be reported as far as 30km away.

Authorities have issued an ashfall advisory for the island’s southernmost district.
Officials also reported Tuesday that a new lava fissure opened in the Lanipuna Gardens subdivision near Leilani Estates.

Nearly 20 fissures have opened up in those two subdivisions, destroying more than two dozen homes since the eruption began May 3.

Lava from another fissure that opened over the weekend is making a path for the ocean, about 3km away.

Volcanic gas and lava have destroyed 37 homes and structures and prompted the evacuation of about 2000 residents.

Geologists warn Kilauea’s summit could have an explosive steam eruption that would hurl huge rocks and ash miles into the sky.

-with AAP