Officials had issued mandatory evacuation orders for Kapoho as well as nearby Vacationland and Leilani Estates, urging those in the area to get out by Friday or risk being unreachable by rescue crews.
Officials said on Saturday that access to Kapoho had been cut off. On Sunday four people were rescued by airlift, according to KITV, but officials with the Hawaii County Civil Defense estimated that "about twelve people" were still trapped in the area.
"There are still people in the inundation zone that cannot, there's no way for them to get out. They're down there, we're seeing them, they're not calling for help yet," said Senator Kai Kahele, who is also a major in the Hawaii Air National Guard.
Those who chose to stay may have to pay the bill for their rescue, KITV reported.
Kahele said the devastation in the area was unprecedented.
"This is something most of us will never see in our lifetime," he said.
About two dozen recent fissures have appeared since the volcano began erupting on May 3, destroying dozens of homes.
The Associated Press contributed to this report.