The Indonesian volcano Mount Sinabung has erupted, sending ash several kilometres into the air.
Local villages were pelted with rocks while visibility was reduced to just a few metres as the eruption took place.
The authorities have also warned of the risk of flight disruption around the island of Sumatra, home to over 50 million people.
For now, no casualties have been reported, but members of the public are being reminded to stay out of the high-risk zone.
The areas immediately surrounding the summit have been off-limits for several years because of the risk of eruption.
Mount Sinabung has killed several people since it became active in 2010, following centuries of dormancy.
The majority of victims have been agricultural workers and local residents based in the area immediately surrounding the mountain. Travellers such as tourists have not reportedly been harmed.
The local authorities have also warned of potential disruption to flights in the area. The Volcano Observatory Notice for Aviation (VONA) level has been raised from orange to red – the highest warning level of the Indonesian body.
At the time of writing, open reports indicate that Kutacane airport in Aceh province has been closed. Kualanamu International Airport, located around 75km northeast of the volcano in Medan remains open. Meulaboh and Silangit airports are also reportedly still open.
With winds blowing the ash cloud several miles to the north, northwest and south-southeast of the volcano, medical organisations have also warned that people in the area may suffer breathing difficulties.
Travellers are advised to review their flight status and be prepared for possible delays, particularly if they intend to fly to or around Sumatra.
Those in the area are advised to stay away from the high-risk zone. Given the potential for further disruption and the spread of ash it might be preferable to seek transport out of the area.
Otherwise, however, the impact on travellers and the millions of residents on Sumatra island is likely to be minimal.
As was the case in Bali in late 2017 when travellers were concerned about the eruption of Mount Agung, the impact will likely be limited to flights, as well as a relatively small area land around the volcano itself. The majority of tourist resorts and settlements lie far from the hazardous zones.
Indonesia ranks at 27 out of 251 in the Starling Disaster Vulnerability Index (with 1 being the most vulnerable and 251 the least vulnerable), putting it in one of the worst brackets in the world.
Not only is the country hit by regular disasters, the authorities often struggle to deal with the aftermath.
The country suffers from regular storms and flooding, but it is particularly affected by seismic activity.
Indonesia sits on the ‘Ring of Fire’ tectonic zone and contains more volcanoes than any other country in the world.
Eruptions have killed hundreds of people and forced hundreds of thousands more to evacuate their homes in the past decade alone.
Mount Merapi on the island of Java is the country’s most active volcano.
Regarded as a ‘Decade Volcano’ by the International Association of Volcanology and Chemistry of the Earth’s Interior, it is deemed worthy of particular study because of its historical activity and proximity to human populations.
The country also suffers from earthquakes and other related seismic activity.
In 2004 the Boxing Day earthquake and tsunami left over 220,000 Indonesians dead or missing.