Hundreds of residents sought shelter on Friday after red-hot lava seeped from Hawaii's Kilauea volcano and plumes of ash and dangerous gases spewed into the air.
Drone footage of the volcanic eruption on Hawaii's Big Island showed orange magma gushing up from cracks in the ground in a wooded area.
Authorities ordered a mandatory evacuation of Lanipuna Gardens and the Leilani Estates neighborhood, home to about 1,700 people and 770 structures.
No injuries have been reported.
Governor David Ige said residents were being housed in community centers until the danger from Kilauea, one of the world's most active volcanos, has passed.
Ige signed an emergency proclamation releasing disaster funds to Big Island.
"Hawaii Fire Department reports extremely high levels of dangerous Sulfur Dioxide gas detected in the evacuation area," the Hawaii County Civil Defense Agency said.
It said there had been "active volcanic fountaining" in the Leilani Estates area, located several miles from the summit of the Kilauea volcano.
Aerial footage showed orange lava bubbling up from a fissure around 500 feet (150 meters) long and spouting into the air like a fountain.
The eruption began around 4:45 pm local time Thursday 0245 GMT Friday) and stopped at around 6:30 pm local time, according to the US Geological Survey (USGS).
The USGS warned, however, that "the opening phases of fissure eruptions are dynamic and uncertain.
"Additional erupting fissures and new lava outbreaks may occur," it said.
The eruption came after hundreds of small earthquakes in recent days that followed the collapse of a crater floor on the Puu Oo volcanic cone.
A 5.0-magnitude earthquake on Thursday morning south of the cone triggered rockfalls and potential additional collapse of the crater, USGS said.
It sent a short-lived but massive pink plume of ash wafting into the air.
Big Island resident Janice Wei, who moved to Hawaii from California -- known for its high earthquake risk -- said the eruption was almost a "relief."
"We've been waiting for big movement from the crater, after so many small earthquakes," she told AFP.
"Hawaiians and local people have lived here forever," she said. "You know what's going on; we have warning systems."
"Everybody should be prepared."
The broader district potentially impacted by the threat is home to some 10,000 people.
Using his drone, area resident Jeremiah Osuna captured video footage of the lava flow, which he described as a "fire curtain" that left him feeling "shock and awe."
"It was like if you put a bunch of rocks into a dryer and turned it on -- a lot of earth and pressure and fire just moving around," Osuna told AFP.
Governor Ige activated the state's National Guard troops, and told residents to pay heed to official warnings.
In his emergency declaration, the governor noted the current flow was similar to a 1960 eruption in the Kapoho area that "caused significant damage."
Geologist Janet Babb of the Hawaiian Volcano Observatory told AFP that scientists had been following an "intrusion of magma" down the rift zone since Monday afternoon in anticipation of a possible eruption.
Though the cracks from which lava was emitting had gone dormant, she emphasized that "the overall concern and the overall event has not ended."
US Senator Brian Schatz of Hawaii said the Federal Emergency Management Agency (FEMA) was mobilizing resources, as well as monitoring for forest fires, power outages and water supply issues.
Hawaii Island, or the Big Island, is the largest of the eight main islands that comprise the Pacific US state, an archipelago that includes hundreds of smaller volcanic islands.