Incredible footage of the infamous Krakatoa volcano emerged as it erupted, spewing a large plume of ash stretching nine miles into the air.

The loud eruption was reportedly heard by residents about 150km away in Jakarta, capital city of Indonesia , at around 11pm on Friday.

A live-feed footage recorded by volcano tracking site Volcano Discovery shows lava fountaining from the volcano.

It spews a column of ash 15 kilometres into the sky in the longest eruption since the explosive collapse of the island caused a deadly tsunami in 2018.

Volcano Discovery wrote: "Both the webcam on Anak Krakatau Island and from the coast (in 40 km distance) show strong lava fountaining from the volcano.

"A large magmatic eruption is taking place at the volcano right now. Based on satellite imagery, VAAC Darwin spotted a high-level ash and SO2 plume reaching 47,000 ft (15 km) altitude moving WNW.

"This seems to be the strongest eruptive phase since the violent phreatomagmatic activity following the partial collapse of the volcano on 22 Dec 2018, which had triggered a deadly tsunami that killed hundreds of people on Java's west coast."

An observation of the Indonesian geological agency showed that three mountains were on "alert" statue, including mount Anak Krakatoa.

The eruption in 2018 (pictured) triggered a killer tsunami in Indonesia

Local residents also shared on Twitter when the eruption started.

One said: "Please stop making that booming noise and go to bed, Anak Krakatau. It's late and we've already got plenty of other things to worry about."

Another one commented: "Krakatau is erupting nonstop for 2 hours. I live in Bogor and I can hear the noises as clear as everybody else hear. This feels like a nightmare."