The volcano has destroyed 26 homes and forced 1,700 people to leave their residences since Friday's eruption, spewing lava and toxic gas from volcanic vents in the eastern corner of Hawaii's Big Island, home to about 200,000 people.
A new fissure opened Sunday night in the Leilani Estates area some 12 miles (19 km) from the volcano, prompting a cellphone alert for residents to leave homes to avoid sulfur dioxide gas, which can be life threatening at high levels.
So far no deaths or major injuries have been reported, the Hawaii County Civil Defense Agency said.
Evacuees from Leilani Estates were allowed to return for pets, medications and to check property on Sunday. Jeremy Wilson found his home surrounded by fissures hundreds of feet long.
"My house is right in the middle," said Wilson, a 36-year-old social worker who turned back when he saw steam coming from cracks in the road.
Early Monday, 161 people were housed at two shelters on the island, the Hawaii County Civil Defense Agency said.
The semi-rural wooded area of Leilani Estates had become a magnet for newcomers to Hawaii who were prepared to risk living near an active volcano for more affordable real-estate.
Eruptions of lava and gas were expected to continue, along with aftershocks from Friday's 6.9 magnitude earthquake, the largest in the area since 1975, according to the Hawaiian Volcano Observatory.
Jessica Gauthier, 47, said she and other local real estate agents had seen vacation renters cancel their reservations, though the volcanic activity is far from tourist centers.
"There's no way to know that if you're sitting in your living room in Ohio and watching the national news," she said.
Hawaii's 4,028-square-mile (10,432-square-km) Big Island accounts for less than a fifth of the state's tourism. State data show that in the first three months of 2018, 16 percent of the $4.81 billion visitors spent in Hawaii came from the big island, less than half of the levels seen in Oahu and Maui.
Gauthier predicted tourism would pick back up as a new kind of visitor began to appear.
"Within a month we'll start getting lava tourists," she said.
Hawaii authorities asked lava watchers to keep away, saying, "This is not the time for sightseeing."