Indonesia villagers race to escape eruption as sky turns black

Locals fled on motorbikes sometimes three at a time as a mushroom cloud of ash approached and monsoon rains lashed the area in East Java.

"It was dark and raining. The rain did not consist only of water, but also volcanic ash. It was like mud," said  journalist on the scene.

Indonesian authorities raised their alert level for the volcano to its highest after the crater spewed hot ash a mile into the sky.

It came only a year after the volcano last erupted, killing at least 51 people and laying waste to homes.

Rescue workers were once again rushing to evacuate villagers in the area Sunday as a colossal plume of ash engulfed all light.

One emergency responder, Gunawan, filmed the clouds above as a midday sky turned ominously dark as though midnight.

"It's getting dark, bro," he said to the camera as a seismograph whistled in the background.

The internet was down and phone signals were patchy but villagers were alerted to the danger by sirens and the beating of bamboo drums by local volunteers.

Semeru is the highest mountain on Indonesia's main island of Java and lies around 800 kilometres (500 miles) southeast of the capital Jakarta among a cluster of craters in a moon-like landscape.

The Southeast Asian archipelago nation has nearly 130 active volcanoes.