People in Hawaii are facing fresh warnings over toxic fumes produced when molten rock flows into the ocean, as the state continues to battle eruptions from the Kilauea volcano.
Officials say two lava flows have reached the Pacific, creating thick hazardous clouds known as "laze".
The clouds contain hydrochloric acid and glass particles which can cause irritation and breathing difficulties.
The US Geological Survey describes laze as a "hot, corrosive, gas mixture".
When molten lava hits seawater, the chemical reaction can create "hazy and noxious conditions", the USGS said in a statement.
It added that "even the wispy edges" of the clouds were enough to cause irritation.