Sept. 30 (UPI) -- A volcano on Hawaii's Big Island started erupting on Wednesday afternoon, officials said.
The U.S. Geological Survey said in an advisory that Kilauea volcano began erupting at 3:20 p.m., when officials with the USGS Hawaiian Volcano Observatory detected a glow in Halemaumau crater in the summit of Kilauea, indicating an eruption was in progress.
"Webcam imagery shows fissures at the base of Halemaumaua crater generating lava flows on the surface of the lava lake that was active until May 2021," the advisory said.
The volcano sits within Hawaii Volcanoes National Park on the Island of Hawaii.
Officials said the primary issue for safety is the high levels of volcanic gas emitting from the mountain, which could "have far-reaching effects down-wind."
The eruption follows the USGS HVO observing increased earthquake activity and changes in the pattern of ground deformation at the mountain's summit.
Ken Hon, HVO scientist-in-charge, told Hawaii News Now that the eruption had a "very rapid onset" and was completely confined to Halemaumaua crater.
"Lava is basically flooding the bottom of Halemaumaua at this time but there is no real high fountaining that can be seen outside of the caldera," Hon said.
Hawaii Volcanoes National Park said thousands of people have descended on the park to watch the eruption.
"Viewing lava at the summit of Kilauea is awe-inspiring. During this COVID-19 pandemic, we ask the public to recreate responsibly, maintain social distance and to wear a mask," Hawaii Volcanoes National Park Superintendent Rhonda Loh said in a statement.
The USGS HVO has elevated the alert level for Kilauea from Watch, meaning the volcano is exhibiting heightened unrest with increased potential of eruption, to Warning as a hazardous eruption is underway.
Officials also lifted its aviation color code from Orange to Red.
The eruption comes four months after the previous eruption at Kilauea, which began in December, ended in May.
In May 2018, thousands of residents in the Puna community of Hawaii Island were urged to evacuate due to a Kilauea eruption.