A volcanic eruption in Indonesia has killed at least two people and forced mass evacuations.

International airports have also been shut, disrupting long-haul flights.

Mount Kelud, considered one of the most dangerous volcanoes on the main island of Java, spewed red-hot ash and rocks high into the air late last night just hours after its alert status was raised.

TV images showed ash and rocks raining down on nearby villages.

A man and a woman, both in their 60s, were crushed to death after volcanic material blanketed rooftops, causing their separate homes in the sub-district of Malang to collapse.

Around 200,000 people in a 10km radius from the volcano were ordered to evacuate, according to national disaster officials.

"Over 100,000 people have been evacuated and about 200,000 people were affected," National Disaster Mitigation Agency spokesman Sutopo Nugroho said.

However, many tried to return to their homes to gather clothing and valuables - only to be forced back by a continuous downpour of volcanic materials.

Virgin Australia said it had cancelled all its flights to and from Phuket, Denpasar, Christmas Island and Cocos Island today, saying in a statement that "the safety of our customers is the highest priority" and that the airline would keep monitoring the plume.

A spokeswoman for Australian airline Qantas said that today’s flights between Jakarta and Sydney had been pushed back to Saturday.

"Flight paths from Australia to Singapore have been altered as a result of the volcanic ash cloud in Java," she said.

The ash has blanketed the Javanese cities of Surabaya, Yogyakarta and Solo, where international airports have been closed temporarily, Transport Ministry director general of aviation Herry Bakti said.

Metro TV showed images of grounded planes covered in ash.

"All flights to those airports have been cancelled, and other flights, including some between Australia and Indonesia, have been rerouted," Mr Bakti said.

"We will reassess the situation tonight regarding reopening the airports, but at the moment, it's too dangerous to fly anywhere near the plume."

On the outskirts of Yogyakarta, authorities closed Borobudur - the world's largest Buddhist temple, which attracts hundred of tourists daily - after it was also rained upon with dust from the volcano some 200km east.

At a temporary shelter in the village of Bladak, roughly 10km from the volcano's crater, around 400 displaced people, including children, slept on the floor wearing safety masks.

The Center for Volcanology and Geological Hazard Mitigation said there was little chance of another eruption as powerful as last night's, but tremors around the volcano could still be felt today as volcanic materials continued to blanket the rooftops of entire villages.

The 1,731m 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 that left at least 16 people dead and has been erupting on an almost daily basis since September.