Tourists pelted by rocks as volcano erupts in front of them and their Kiwi tour guide

A New Zealand-based cameraman has captured the terrifying moment a volcano erupted and pelted huge rocks into the air.

Geoff Mackley, who has spent years filming volcanoes in Aotearoa and around the world, was taking a group on a guided tour of the Krakatoa Volcano in Indonesia on Monday (local time) when the volcano began to erupt.

The footage shows the boat steering away from the huge on-coming rocks, which are being thrown from the volcano.

Despite the rocks not damaging the boat or hurting anyone, Mackley says things could've easily turned deadly.

"In the video, you can see a big explosion and rocks hitting the sea very close to us," he says.

"The rocks were big enough to kill us, and would definitely have sank our boat if they hit it."

Mackley says he gives tourists a unique experience by "deliberately seeking out encounters with nature as safely as possible".

He reckons he wasn’t fazed by the dramatic eruption.

"Other items have landed close in the past or fallen on me in hurricanes, so I wasn't too worried."

Caters/Newshub.