THE Hawaii State Department of Health has issued a warning that gases from the current volcanic activity is potentially dangerous and advised local residents to leave the area.

People living in the lower Puna area of the Big Island have been issued with a warning that sulfur dioxide emissions are present at dangerous levels.

The department sent the following warning: “Leaving the area of volcanic activity or sheltering in place is the best way to protect yourself and your family. Only specialised masks will protect from dangerous gases and particulate matter that are being released.”

The “elderly, young children and babies and people with respiratory problems” are particularly at risk.

The warning comes as a new volcanic fissure formed on the Kilauea volcano.

The new eruption was reported on Monday in the Lanipuna Gardens subdivision, an area that has already been evacuated. Civil defence officials warn of volcanic gas emissions and active eruptions with this new fissure.

It is the 18th fissure to open on the volcano since it began erupting on May 3. A separate fissure is still active after it formed on Sunday (local time).

The Hawaiian Volcano Observatory says a lava flow has now formed and is slowly moving toward the ocean, which is about 3.2 kilometres away. No homes or roadways are threatened by this flow.

Kilauea began erupting on May 3. Since then, fissures have been generated mostly in Leilana Estates subdivision, where nearly 2000 residents were ordered to evacuate. Lava has destroyed more than 40 structures, including two dozen homes.

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

Residents in the immediate area have already been told to evacuate, and two nearby community centres are serving as shelters for people and pets.

Lava has spread across hundreds of metres of private land and loud explosions have rocked the neighbourhood not far from Leilani Estates subdivision, where more than a dozen other active vents have opened in the past week.

Nearby resident Richard Schott, 34, sat near a police checkpoint and watched as one eruption churned just over a ridge line and behind some trees.

“I’ve actually seen rocks fly over the tree line and I can feel it in my body,” Schott said.

“It’s like a nuclear reaction or something.”

The new opening was still showing signs of activity.

“It is a near-constant roar akin to a full-throttle 747 interspersed with deafening, earth-shattering explosions that hurtle 45kg lava bombs 30 metres into the air,” said Mark Clawson, 64, who lives uphill from the latest fissure and so far is defying an evacuation order.

Closer to the summit, in the evacuated Leilani Estates neighbourhood of about 1500 people, explosions could be heard in the distance as steam rose from cracks in the roads. The bulging rim of one fissure wrecked a building, leaving behind torn metal.

In areas where sulfur dioxide emissions were strong, the vegetation turned brown and leafless trees withered.

Meanwhile, other fissures continued to billow smoke over homes on the eastern point of the Big Island of Hawaii, the largest of the Hawaiian Islands. Even so, some people such as Clawson remained in their homes, confident they would be spared.

“We are keeping track of lava bombs. One went through the porch roof of a neighbour’s house,” Clawson said. About eight to 10 neighbours had yet to evacuate, he said.

The Hawaii National Guard warned people in the coastal Lower Puna area to prepare to leave, saying anyone who chooses to stay behind cannot count on being rescued. An evacuation has not been ordered there but might be if a local highway is cut off.

“We’ve been telling them, ‘Evacuate if you can, because if we have to come in and get you we’ll be putting first responders at risk’,” Major Jeff Hickman told reporters. “There’s a point where we’ll tell our first responders, ‘Nope, you can’t go’.”

The U.S. Geological Survey’s Hawaiian Volcano Observatory said new fissures, ground deformation and abundant volcanic gases indicate eruptions on the eastern flank of Kilauea are likely to continue.

“The appearance of the fissures in the past couple of days does not change the overall picture or concern,” USGS scientist Steve Brantley said.

Christian and Maritza Ricks, who moved to the area from California in April, stopped on the side of the road to watch and listen to the latest eruption.

“I guess it’s just part of living on the island,” Ricks said.

He said he wasn’t really afraid of the destruction happening around him.

“In a way it’s kind of exciting to see what’s going on and be this close to it.”

The Hawaiian Volcano Observatory reported the fissures opened just east of the Puna Geothermal Venture energy conversion plant, where steam and hot liquid are brought up through underground wells and the steam feeds a turbine generator to produce electricity.

Plant workers last week as a precaution removed 189,265 litres of a flammable gas stored at the site. Geologists warn that Kilauea’s summit could have an explosive steam eruption that would hurl huge rocks and ash kilometres into the sky.