agung volcano
© Reuters / Wayan Kartika
Mount Agung erupts in Bali, Indonesia on May 24, 2019
Bali's airport has cancelled flights following an eruption of the Mount Agung volcano that spread ash over the Indonesian island's south.

The national disaster agency said Friday night's eruption lasted four minutes and 30 seconds and spread lava and incandescent rocks about three kilometres from the crater.

Nine villages experienced thick ash fall. But the agency said it wasn't raising the alert level for the volcano and its exclusion zone remains a four kilometre radius around the crater.

The Directorate General of Air Transportation said four flights to Bali were diverted and five flights out of the popular tourist destination were cancelled because of volcanic ash.

Agung became active again in 2017 after more than a half century of slumber following a major eruption in 1963.

The eruption in 1963 killed about 1100 people.

Agung lies about 70 kilometres northeast of Bali's tourist hotspot of Kuta.

It is among more than 120 active volcanoes in Indonesia, which is prone to volcanic eruptions and earthquakes because of its location on the so-called "Ring of Fire" — a series of fault lines stretching from the Western Hemisphere through Japan and Southeast Asia.