A volcanic eruption in Indonesia has prompted an aviation warning in Australia, after ash spewed into the sky.
Indonesia's Mount Semeru volcano, Java Island's tallest mountain, erupted on Wednesday, local time, prompting authorities there to raise the threat level to its highest.
The country's volcanology agency said ash clouds reached up to 5.6 kilometres into the sky, roughly 2km higher than the mountain peak.
Clouds of hot ash and a mixture of rock, lava and gas travelled up to 7km down Mount Semeru's slopes several times from midday to dusk.
It blanketed several villages, but no casualties have been reported.
[MAP]More than 300 residents at risk in the district of Lumajang have been evacuated to government shelters, according to the National Disaster Mitigation Agency.
Authorities widened the danger zone to 8km from the crater.
Local media reported that authorities were struggling to rescue 178 people stranded at a monitoring post 4.5km from the crater.
The group includes 137 climbers, 15 porters, seven guides and six tourism officials, according to an official with the Bromo-Tengger-Semeru National Park, TNBTS.
"They are currently safe," a TNBTS spokesperson said.
The Australian Bureau of Meteorology's Volcanic Ash Advisory Centre (VAAC) issued a red aviation alert following the eruption.
The VAAC said the ash was "partially identifiable on satellite imagery".
No flights have been cancelled between Australia and Denpasar airport because of the eruption.
At more than 3,600 metres high, Semeru is one of Indonesia's nearly 130 active volcanoes.
It has erupted numerous times in the past 200 years, but tens of thousands of people continue to live on its fertile slopes.
Semeru's last major eruption in December 2021 left 51 people dead and several hundred others burned in villages that were buried in layers of mud.
About 10,000 people were evacuated, and the emergency prompted the government to move nearly 3,000 houses out of the danger zone.
Indonesia straddles the "Pacific Ring of Fire", a highly seismically active zone, where different plates on the Earth's crust meet and create a large number of earthquakes and volcanoes.
ABC/wires
