A NEW fissure roaring like jet engines and spewing magma has opened on Hawaii’s Kilauea volcano, piling lava as high as a four-storey building, as the area torn by the volcano’s eruption spread.

The crack in pasture land on Kilauea’s east flank was the 16th recorded since the volcano, one of the world’s most active, erupted eight days ago.

Thousands of people have fled their homes on Hawaii’s Big Island because of lava and toxic gases, and dozens of homes have been destroyed.

The new fissure opened up about a 1.6km east of the existing vent system that has devastated the island’s Leilani Estates neighbourhood, with a few homes on the edge of the field where the vent opened on Saturday. The US Geological Survey warned that more outbreaks remained likely.

Shortly after the fissure opened, the Geological Survey’s Hawaii Volcano Observatory said seismic activity remained “elevated” at Kilauea’s 1200-metre summit. The USGS reported a shallow but small earthquake with a magnitude of 3.5 hit the island on Saturday.

Geologists warned on Friday that a steam-driven eruption from the summit’s Halemaumau crater could spew ash plumes 6100 metres high and spread ash and debris up to 20km.

As the area affected by Kilauea’s eruption widens, Hawaii residents are racing to buy respirators to cope with the ash and toxic gases spewing from the volcano.

The news comes as US President Donald Trump approved the Hawaii Governor’s request for a presidential disaster declaration for the Big Island as the state copes with Kilauea volcano’s eruption.

Hawaii Governor David Ige said the declaration means federal assistance will be available as the state covers costs associated with damaged roads, public parks, schools and water pipes.

It will also cover costs for geologists and security personnel at roadblocks.

The approval came a day after Gov. Ige requested the declaration.

Kilauea volcano began erupting lava into a residential neighbourhood on the Big Island on May 3.

So far, it has destroyed 36 structures, including 26 homes.