LUMAJANG (Indonesia) - Rescuers evacuated more people on Monday from nearby villages after the eruption of Indonesia’s Mount Semeru, with officials warning of danger from cooling lava despite less activity from the volcano.

More than 2,400 villagers have now fled their homes and taken shelter in 11 evacuation centres after the highest mountain on the country’s main island of Java erupted early on Sunday morning.

Officials have announced a state of emergency for the next two weeks and the authorities have been distributing free masks for protection against ash in the air and setting up public kitchens for evacuees.

Mr Abdul Muhari, a spokesman for Indonesia’s disaster mitigation agency, said that visual observation of Semeru on Monday morning indicated less intense volcanic activity. But he warned of potential danger from lava flows that had cooled after heavy rain.

“What we worry about is economic activities such as sand mining. We want to make sure the route where the hot ash cloud and the cold lava might travel is completely free of activity,” he said.

No casualties have been reported and there has not been any immediate disruption to air travel.

The 3,676m volcano erupted on Sunday at 2.46pm local time (3.46pm, Singapore time). Footage shot by local residents showed Mount Semeru spewing a giant cloud of grey ash high above its crater, which later engulfed the mountain and surrounding rice paddy fields, roads and bridges, and turned the sky black. A video shared by the Environment Ministry on Twitter showed a pyroclastic flow of lava, rocks and hot gases gushing down the mountainside.

Indonesia’s volcanology and geological hazard mitigation agency on Sunday raised the alert level for Mount Semeru to the highest level. It also issued a warning to residents not to go within 8km of the summit or 500m of riversides due to the risk of lava flow.

Mount Semeru erupted in 2021, killing more than 50 people and displacing thousands more.

The eruption, some 640km east of the capital, Jakarta, follows a series of earthquakes in the west of Java, including one in November that killed more than 300 people.

Indonesia, an archipelago of 270 million people that sits along the Pacific Ring of Fire, is one of the most disaster-prone countries.

With 142 volcanoes, Indonesia has the largest population globally living in close range to a volcano, including 8.6 million within 10km. AFP, REUTERS