Nearly 2,000 people have been evacuated since the volcano erupted May 3, sending lava flowing into communities and threatening a nearby geothermal plant.
An 18th fissure, a crack on the ground through which lava pours out, was reported Sunday, according to the Civil Defense Emergency System for the County of Hawaii.
The Department of Public Works and Police said the new fissure opened on Hale Kamahina Loop Road and is emitting steam and lava.
The fissure is several hundred yards long and splattering lava tens of feet into the air, according to the Hawaiian Volcano Observatory.
Residents along the road have been ordered to evacuate, officials said.
The 17th fissure was reported Saturday night, the US Geological Survey's Hawaiian Volcano Observatory said.
"Lava from this latest outbreak is actively spattering," it said.
The volcanic vents, or fissures, have released slow-moving lava and toxic gas into island communities, gobbling up dozens of homes and vehicles.
Another fissure, the 16th, was reported earlier Saturday and "produced a lava flow that traveled about 250 yards before stalling," officials said.
That vent was about a mile east of the Puna Geothermal Venture plant, where officials removed 60,000 gallons of flammable liquids due to safety concerns.
In addition to the new fissures, USGS officials said an explosive eruption is possible at Halemaumau crater at the top of the Kilauea volcano. Such an eruption could generate ash plumes over an area 12 miles from the summit crater, the HOV said.