A New Zealand volcano has erupted for the first time in more than a century, causing travel chaos, with flights cancelled and roads covered in ash.
Mt Tongariro on the North Island erupted late on Monday night - and experts have issued warnings that the volcano could explode again.
Thick grey ash covered the area around the volcano for several miles, and the debris rained down for 30 minutes.
New Zealand's Mt Tongariro, which erupted on Monday
Volcanologist Michael Rosenberg told Radio New Zealand: "For the moment, things are quiet but it doesn't necessarily mean that the eruption is over and done with. It could reactivate at any time so we're watching pretty closely.
"It's possible that this could be the start of a much longer episode, or alternatively it could be the end. We just don't know."
Scientists have recorded increased seismic activity since July, but were taken by surprise by the small-scale eruption, which they believe was driven by steam pressure inside the mountain, rather than molten rock.
The Ministry of Civil Defense and Emergency Management advised residents of five nearby communities to stay indoors and to protect their eyes, mouth and nose if they were caught in volcanic ash.
Mt Tongariro last erupted from November 1896 until October 1897.
Volcanic ash fell on a properties near the base of Mt Tongariro, New Zealand
Hundreds of travellers have been stranded by the volcanic ash, causing Air Zealand flights to be cancelled.
Locals said no-one had been injured and no property damaged, apart from dirty ash on clothing, buildings and vehicles, but there was a "sulphur" smell in the air.