ABOUT 200,000 Indonesians have been ordered to leave their villages after a volcano on the main island of Java erupted.

The eruption of Mount Kelud, in eastern Java, caused widespread disruption to flights in the area, with flights into the area cancelled, the ABC has reported.

Airports at Surabaya and in the cities of Yogyakarta and Solo were closed, while Qantas announced it was cancelling this afternoon's flight from Sydney to Jakarta.

Mount Kelud, located in Kediri district, is considered one of the most dangerous volcanoes on the densely populated island.

National disaster agency spokesman Sutopo Purwo Nugroho says a rain of ash, sand and rocks is falling on an area stretching 15 kilometres from the volcano's crater.