Hundreds of thousands of Indonesians were ordered to evacuate Friday after a volcano on the main island of Java erupted spectacularly, hurling red hot ash and rocks over a huge distance.

The alert status for Mount Kelud, considered one of the most dangerous volcanoes on densely populated Java, was raised late Thursday just hours before it began erupting.

TV pictures showed ash and rocks raining down on nearby villages as terrified locals fled in cars and on motorbikes towards evacuation centres.

National disaster agency spokesman Sutopo Purwo Nugroho said that some 200,000 people from 36 villages in a 10-kilometre (six-mile) area around Kelud, in Kediri district in eastern Java, were being asked to evacuate.

"A rain of ash, sand and rocks is reaching up to 15 kilometres (nine miles)" from the volcano's crater, he said.

"Sparks of light can be continuously seen at the peak."

The 1,731-metre (5,712-foot) Mount Kelud has claimed more than 15,000 lives since 1500, including around 10,000 deaths in a massive 1568 eruption.

It is one of some 130 active volcanoes in Indonesia, which sits on the Pacific Ring of Fire, a belt of seismic activity running around the basin of the Pacific Ocean.

Earlier this month another volcano, Mount Sinabung on western Sumatra island, unleashed an enormous eruption, leaving at least 16 people dead.

Sinabung has been erupting on an almost daily basis since September, coating villages and crops with volcanic ash and forcing tens of thousands out of their homes.