JAKARTA: A volcano erupted spectacularly on the Indonesian island of Sumatra early yesterday morning, sending plumes of ash, sand and steam 1500 metres into the sky and prompting the evacuation of 12,000 nearby residents.

Mount Sinabung has not erupted for more than 400 years and authorities admitted yesterday they had not been monitoring it closely and knew little about its potential for further explosions.

Exodus . . . a father and son look on as Mount Sinabung burns, spreading ash up to 30 kilometres away. Credit:AFP/Sutanta Aditya

The 2460-metre volcano in the north of Sumatra began fizzing and spitting smoke for several hours on Friday, emitting loud noises and panicking residents.

Grey ash continued to gush from the volcano on Saturday but authorities remained confident that it would not erupt. Those calculations proved misplaced when it did just that after midnight on Sunday.