One woman was in serious condition with a fractured femur.
Genuinely terrifying video footage shows passengers watching freshly erupted lava mingle with the Pacific Ocean, shortly before a hazy explosion sends ballistics flying their way.
Other passengers suffered minor injuries including burns, scrapes and superficial injuries.
It seared through the material and crashed into the seating area, said Hawaii County Fire Department Battalion Chief Darwin Okinaka.
The U.S. Geological Survey says explosions of varying sizes happen whenever 2,000-degree (1,093-degree Celsius) lava enters much colder seawater.
Government officials have also been warning about the dangers of laze, potentially unsafe mix of hydrochloric acid, steam and tiny glass particles in the air that results from the interaction of the lava and the water.
UPDATE, PHOTOS: 13 Injured as Lava Bomb Rips Through Tour Boat Roof
Boat and helicopter tours are the only ways people are able to see Kilauea for themselves, as land access is restricted due to safety issues.
"As we were exiting the zone, all of a sudden everything around us exploded".
23 people were injured when lava was hurled into a boat touring the Kilauea lava flow on Hawaii's Big Island on Monday.
Boats are generally barred from encroaching within 300 metres of lava ocean hot-spots.
Salespeople for helicopter lava tour companies Blue Hawaiian Helicopters and Paradise Helicopters said it was business as usual on Tuesday and they had seen no cancellations. However, certain commercial and research vessels with licensed captains demonstrating experience operating in the region and carrying all required safety equipment were given special permission to approach up to 50 meters.
Continued lava flows, earthquakes and slumping caused by Kilauea have devastated Hawaii's Big Island.
Residents on Big Island have been forced to flee their homes while ash and lava destroyed 600 buildings, as well as created toxic air in certain areas.
China’s U.S. trade surplus hits record on rush to beat tariffs
The dispute has jolted global financial markets, raising worries a full-scale trade war could derail the world economy. As the US-China trade war escalates, the latest trade numbers appear to back Washington's biggest gripe with Beijing.
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