"We're observing more or less continuous emission of ash now with intermittent, more energetic ash bursts or plumes", Hawaiian Volcano Observatory (HVO) Deputy Scientist-In-Charge Steve Brantley told reporters.
Still, ash plumes had spouted as high as 12,000 feet into the air in the past couple of days.
Two more fissures also had opened, bringing the total to 21 since the first eruptions on May 3, HNN reported. Much of the park remains closed. "We live on a volcano!"
Hawaii Governor David Ige said the state is forming a joint task force that could handle mass evacuations of the Big Island's Puna district if lava from Kilauea volcano covers major roads and isolates the area.
Geologists with the Hawaii Volcano Observatory have said activity at Halemaumau Crater shows indicative signs of potential steam-driven explosions. Because there's little wind, the plume for the most part is rising vertically over the summit.
Because of the ash, USGS scientists operated from a backup command centre at the University of Hawaii at Hilo. They will have to rely on remote observations, he said.
Signs of bomb found at site of deadly SoCal explosion
Pieces of the device found at the scene were being sent to the FBI's laboratory in Quantico, Virginia, to be analyzed, he said. Witnesses spoke of a loud crash and said they saw two women who had been burned in the explosion come out of the building.
Mike Poland with the U.S. Geological Survey said Wednesday the plume seems to be made largely of rock dust. But it's not certain when or if that might happen.
Volcanic gas and lava have destroyed 37 homes and structures and prompted the evacuation of about 2000 residents.
The area taking the brunt of the eruption is about 25 miles down Kilauea's eastern flank, near the village of Pahoa. Most fissures are in that subdivision or the adjoining Leilani Estates neighbourhood.
Several fissures shot lava into the air on Wednesday but the flow from number 17 had not advanced any further toward coastal Highway 137, which remains around a mile distant, County of Hawaii Civil Defense said in a statement.
Another fissure that opened up last weekend is sending molten rock crawling towards the ocean at about 20 yards per hour.