This is the moment the South Pacific island of Tonga was hit by a tsunami after an underwater volcano erupted on Saturday (January 15).

The eruption triggered a 1.2-metre tsunami wave and evacuation orders and much of the island remains uncontactable after communications were cut off.

Video filmed by Dr Faka’iloatonga Taumoefolau at Kolomotu’a near the ocean shows waves crashing ashore. "Can literally hear the volcano eruption, sounds pretty violent," he wrote on Twitter on Saturday.

Newsflare was able to reach Taumoefolau by email on Monday morning local time.

"Only just got to work where we have internet. The rest of the country is cut off," Taumoefolau said.

"My understanding is we have been advised not to use water from watertanks as drinking water," he added.

"Authorities are still trying to reach the most vulnerable in the communities and adjacent islands to Tongatapu," Taumoefolau told Newsflare. "I have not heard what the latest situation is with the volcano or the tsunami but here on Tongatapu a lot of people are out and about trying to clean the debris, ash and fix the extensive damages to their homes.

"This is the second tsunami I have experienced here in Tonga (first was the one in 2009, which caused casualties in Tonga and Samoa), so I have a fair idea of how to read it, so to speak. The difference this time round is that it kept coming wave after wave, after the first wave hit (the footage) I evacuated to higher ground. On the waterfront where I lived, homes are either completely destroyed or badly damaged but with the added challenge of the ash/tiny pebbles from the volcano eruption covering everywhere (literally)."

Taumoefolau is a Project Coordinator for the Tonga Parliament Buildings Project.

Volcanic eruption of Hunga Tonga and Hunga Ha'apai that caused the tsunami to the Kingdom of Tonga.

Filmed at Kolomotu’a, Tongatapu, Tonga. The road is Hala Vuna.