Kilauea, one of the world’s most active volcanoes, began erupting around 2:30 a.m. local time within the Halemaʻumaʻu crater, which is part of the much larger Kilauea caldera at Hawaii Volcanoes National Park, News.Az reports, citing foreign media.

Webcam footage showed flowing lava and a line of fissures spewing lava fountains at the base of the crater within the summit caldera, the geological survey said.

The volcano is located along the southeastern shore of the Island of Hawaii within the national park, a popular tourist destination for those hoping to catch glimpses of volcanic activity. A UNESCO World Heritage Site, the park encompasses the summits of two of the world’s most active volcanoes: Kilauea and Mauna Loa.

The USGS Hawaiian Volcano Observatory on Monday raised the volcano alert level from an advisory to a warning, meaning a hazardous eruption “is imminent, underway, or suspected.” The survey also issued a red aviation color code, which indicates a “significant emission of volcanic ash” is likely, suspected or imminent, according to the USGS.

Elevated earthquake activity was first detected beneath the summit at approximately 2 a.m. local time Monday.

The USGS Hawaiian Volcano Observatory said it “will continue to monitor this activity closely and report any significant changes in future notices.”

The national park has not yet posted any visitor information about the volcanic activity.