SOLO, March 3 — Indonesia's most active volcano Mount Merapi erupted today, shooting a massive ash cloud some 6,000 metres in the air which coated nearby communities with grey dust and forced an airport closure.

Ash mixed with sand rained down on towns as far as 10 kilometres from the belching crater near Indonesia's cultural capital Yogyakarta.

"There was a thundering noise for at least five minutes and I could see the ash clouds from my house,” Jarmaji, a resident of Boyolali regency, told AFP.

Authorities did not raise the rumbling volcano's alert status, but they temporarily shuttered the international airport in Solo city — also known as Surakarta — some 40 kilometres away after the early morning eruption.

Indonesia's volcano agency warned residents to stay out of a three-kilometre no-go zone around Mount Merapi, citing possible danger from flowing lava and pyroclastic flows — a fast-moving mixture of hot gas and volcanic material.

Mount Merapi's last major eruption in 2010 killed more than 300 people and forced the evacuation of some 280,000 residents.

That was Merapi's most powerful eruption since 1930, which killed around 1,300 people, while another explosion in 1994 took about 60 lives.

The South-east Asian nation — an archipelago of more than 17,000 islands and islets — has nearly 130 active volcanoes.

It sits on the Pacific "Ring of Fire,” a vast zone of geological instability where the collision of tectonic plates causes frequent quakes and major volcanic activity. — AFP