Kilauea volcano has erupted near a residential area on Hawaii’s largest island, prompting a local state of emergency and the mandatory evacuation of 1,700 residents.
Extremely high levels of dangerous sulphur dioxide gas have been detected in the evacuation area, the Civil Defense Agency tweeted.
Community centres have been opened to provide shelter.
The eruption follows a series of strong earthquakes over recent days.
A volcanic crater vent – known as Puu Oo – collapsed earlier this week, sending lava down the mountain’s slopes towards populated areas.
Officials had been warning residents all week they should be prepared to evacuate as an eruption would give little warning.
Hawaii’s Governor David Ige says he has activated military reservists from the National Guard to help evacuate thousands of people.
I am in contact with @MayorHarryKim and Hawai‘i County, and the state is actively supporting the county’s emergency response efforts. I have also activated the Hawai‘i National Guard to support county emergency response teams with evacuations and security. #Kilauea #Volcano
— Governor David Ige (@GovHawaii) May 4, 2018
Television pictures showed a line of lava fountains from Kilauea bursting up under a road and adjoining gardens.
Close-up footage shot by a drone showed lava emerging from a fissure in a wooded residential neighbourhood and oozing down a road.
Earlier this year, a false alert warning of an incoming ballistic missile caused panic, leading the US state to reassess its alert system.