A new fissure in Hawaii's Puna District sent gases and lava exploding into the air on Sunday, spurring officials to call for more evacuations as residents waited for a possible major eruption at Kilauea volcano's summit.

Hawaii County Civil Defense issued an emergency cellphone alert after the fissure was discovered early Sunday morning. The agency said one "unidentified structure" was destroyed by the new vent, bringing the total number of homes and other buildings lost to the lava to nearly 40.

Residents in the immediate area were told to evacuate, and two nearby community centers were serving as shelters for people and pets.

Lava spread across hundreds of yards of private land and loud explosions rocked the neighborhood 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 the eruption churned just over a ridgeline 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 Sunday afternoon. The fissure measures about 1,000 feet (300 meters) long, officials said.

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."

Most of the lava outbreaks have occurred in and around the Leilani Estates neighborhood, where molten rock has burst through the ground, destroying more than two dozen homes and resulting in evacuation orders for nearly 2,000 people.

The U.S. Geological Survey has reported nearly 20 active fissures. One that opened Saturday night was spattering, but no flow had formed.

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 50,000 gallons (189,265 liters) 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 miles into the sky.