A new lava fissure has opened up on Hawaii's Kilauea volcano as residents braced for an expected eruption.
The Hawaii County Civil Defense issued an alert that an 18th fissure was discovered on Sunday along a road west of a major highway on the Big Island. Residents on that road were being told to evacuate.
The fissures, ground deformation, and abundant volcanic gases indicate eruptions on the eastern flank of Kilauea are likely to continue.
Kilauea is threatening to blow its top in coming days or weeks after sputtering lava for more than a week, forcing about 2,000 people to evacuate, and destroying two dozen homes.
Another volcanic fissure, a crack on the ground through which lava pours out, released slow-moving lava and toxic gas on Saturday night into island communities.
"Lava from this latest outbreak is actively spattering and degassing but no flow has yet formed. This area was actively steaming earlier in the day," US Geological Survey's Hawaiian Volcano Observatory said.
Chunks of magma were being spewed 30 metres into the air, and seismic activity remained "elevated" at Kilauea's 1,200-metre-high summit, the observatory said.
Kilauea: Hawaii volcano forces thousands to flee their homes
Two eruptions occurred on Saturday. The latest - confirmed to be the 17th since the lava flows began on May 3 - happened at 6pm (04:00 GMT) about 100 metres below the previous one.
The 16th fissure opened at 6:45am east of the Puna Geothermal Venture plant, where steam and hot liquid are brought up through underground wells and feed a turbine generator to produce electricity.
Residents of lower Puna were advised to be on alert in the event of possible gas emissions and volcanic eruption, Hawaii County Civil Defense said.
"There may be little to no advance notice to evacuate, so take this time to prepare," it said.
Officials told vacation rental operators in lower Puna they were not allowed to offer th