Tonga volcano: Tsunami warnings as US and Japan tell citizens to move away from the shore

Pacific nations and humanitarian groups struggled to establish communications with Tonga on Sunday after a tsunami triggered by a massive volcanic eruption cut telephone and internet connections, raising concerns for the tiny island nation.

An underwater volcano off Tonga erupted on Saturday, triggering tsunami warnings and evacuation orders on the shores of Tonga as well as several South Pacific islands, where footage on social media showed waves crashing into coastal homes.

Tonga's capital Nuku'alofa suffered "significant" damage in the powerful volcanic eruption which triggered a tsunami but there had been no reports of injury or death, New Zealand Prime Minister Jacinda Ardern said on Sunday.

"The tsunami has had a significant impact on the foreshore on the northern side of Nuku'alofa with boats and large boulders washed ashore," Ms Ardern said, adding her government had made contact with the New Zealand embassy in the Tongan capital after communications with the island were cut following the eruption.

US Secretary of State Antony Blinken said he was "deeply concerned for the people of Tonga as they recover from the aftermath of a volcanic eruption and tsunami. The United States stands prepared to provide support to our Pacific neighbors," Blinken said on Twitter.

Internet and phone lines went down at about 6.40pm local time on Saturday (5.40am UK), leaving the 105,000 residents on the islands virtually uncontactable.

The eruption also triggered tsunami warnings on the US west coast and hundreds of thousands of Japanese citizens were advised to evacuate on Sunday as waves of more than a metre hit coastal areas, public broadcaster NHK reported.

Around 230,000 people were advised to evacuate across eight prefectures due to the tsunami risk. The alert included areas hit by the deadly 2011 tsunami.

Ten boats were capsized in Kochi prefecture on Shikoku island in southern Japan, NHK said, and Japan Airlines cancelled 27 flights at airports across the country.

On Sunday morning, the Pacific Tsunami Warning Center said the threat from the tsunami had passed.

"Based on all available data, the tsunami threat from this volcanic eruption has now passed," the PTWC said, adding that authorities at "impacted coastal areas should monitor... to determine when it is safe to resume normal activities".

The International Federation of Red Cross and Red Crescent Societies (IFRC) Pacific Office in Suva, Fiji said it was monitoring the situation and had no updates on damages or casualties.

Tongan churches in New Zealand organised prayers for their families back home.

"We pray God will help our country at this sad moment. We hope everybody is safe," Maikeli Atiola, the Secretary of the Wesleyan Church of Tonga in Auckland said.

The Hunga-Tonga-Hunga-Ha'apai volcano has erupted regularly over the past few decades but Saturday's eruption was so loud that residents parts of faraway Fiji and New Zealand said they heard it.

Satellite images captured the volcanic eruption on Saturday as the explosion sent plumes of smoke into the air and about 12 miles above the sea level.

The sky over Tonga was darkened by the ash.

The eruptions triggered tsunami warnings across the Pacific, with the United States and Japan urging people on their Pacific coastlines to stay away from the shores.

Australia issued a marine tsunami warning for the New South Wales coastlines, Lord Howe Island and Norfolk Island, and said local beaches along the state’s coast have been closed. A tsunami advisory was also issued in New Zealand.