An explosive eruption at Hawaii’s Kilauea volcano has sent ash 30,000ft (9,100m) into the sky.
The eruption took place at 04:15 local time (14:15 GMT) on Thursday, and scientists say further activity is likely in the near future.
Staff at the volcano observatory and the national park had been evacuated.
Since a new zone of Kilauea began erupting almost two weeks ago, lava has wrecked dozens of homes and forced hundreds of people to be evacuated.
A red aviation code had already been issued, warning pilots to avoid the potentially damaging ash cloud.
The US Geological Survey had warned that an explosive eruption at Kilauea was becoming more likely as the volcano's lava lake was lowering.
This increases the risk of steam-powered explosions as the magma meets underground water.
"We may have additional larger, powerful events," USGS geologist Michelle Coombs told reporters after Thursday's eruption.
Hawaii's emergency management agency advised people in the area affected by ash to stay in their homes if possible.
Kilauea is one of five volcanoes on the island of Hawaii - three of them active.
It is one of the most active in the world and has been erupting continuously, though not explosively, for more than 30 years.
Its last explosive eruption took place in 1924.
Even before Thursday morning's explosive eruption, the ash plume from the volcano could be seen from the International Space Station.