Sangeang Api, a volcano off the Indonesian island of Sumbawa, which lies in one of the most active areas of the Pacific 'ring of fire', has erupted at least three times since Friday.

Dramatic images show smoke, ash and debris shooting into the sky, while a flying saucer shaped current of gas wraps around the plumes.

All flights have been cancelled from Darwin airport, Australia's Northern Territory capital, and disruption is expected for days as the cloud could reach as far south as Brisbane.

The ash cloud from the first eruption is around 20,000 and 50,000 feet high and around 15 km wide, according to reports.