Indonesia’s most active volcano erupted on Wednesday with a river of lava and searing gas clouds flowing 4,900ft (1,500m) down its slopes.

It was Mount Merapi’s longest lava flow since authorities raised the volatile volcano’s danger level in November, said Hanik Humaida, the head of Yogyakarta’s Volcanology and Geological Hazard Mitigation Centre.

The alert level was being maintained for now at the second-highest level, she said, and people should stay out of the existing three-mile (5km) danger zone around the crater as the local administrations in Central Java and Yogyakarta provinces closely monitor the situation.

After morning rain, ashfall turned into dirt in several villages, where the sound of the eruption could be heard 18 miles away. Police and rescue services told miners to cease work along rivers but no one was evacuated.

The 9,737ft (2,968m) volcano is on the densely populated island of Java and near the ancient city of Yogyakarta.

It is the most active of dozens of Indonesian volcanoes and has repeatedly erupted with lava and gas clouds recently.

Merapi’s last major eruption in 2010 killed 347 people.

Indonesia, an archipelago of 270 million people, is prone to earthquakes and volcanic activity because it sits along the Pacific “Ring of Fire”, a horseshoe-shaped series of seismic fault lines around the ocean.