The Internet connection has been cut in Tonga where tsunami waves crushed across the shore and people rushed to higher ground.
The tsunami threat around the Pacific from a huge undersea volcanic eruption has began to recede, while the extent of damage to Tonga remained unclear.
New Zealand Prime Minister Jacinda Ardern said there had not yet been any official reports of injuries or deaths in Tonga, but cautioned that authorities hadn't yet made contact with some coastal areas and smaller islands.
“Communication with Tonga remains very limited. And I know that is causing a huge amount of anxiety for the Tongan community here,” Ardern said.
She said there had been significant damage to boats and shops along the Tongan coastline. The capital, Nuku'alofa, was covered in a thick film of volcanic dust, Ardern said, contaminating water supplies and making fresh water a vital need.
Satellite images showed the spectacular eruption that took place on Saturday evening, with a plume of ash, steam and gas rising like a mushroom above the blue Pacific waters.
A sonic boom could be heard as far away as Alaska.
In Tonga, it sent tsunami waves crashing across the shore and people rushing to higher ground.
'Humbling and scary'
The eruption cut the internet to Tonga, leaving friends and family members around the world anxiously trying to get in touch to figure out if there were any injuries and the extent of the damage.
Even government websites and other official sources remained without updates on Sunday afternoon.
Dave Snider, the tsunami warning coordinator for the National Tsunami Warning Center in Palmer, Alaska, said it was very unusual for a volcanic eruption to affect an entire ocean basin, and the spectacle was both “humbling and scary.”
The tsunami waves caused damage to boats as far away as New Zealand and Santa Cruz, California, but did not appear to cause any widespread damage.
Snider said he anticipated the tsunami situation in the US and elsewhere to continue improving.
Tsunami advisories were earlier issued for Japan, Hawaii, Alaska and the US Pacific coast.
The US Geological Survey estimated the eruption caused the equivalent of a magnitude 5.8 earthquake. Scientists said tsunamis generated by volcanoes rather than earthquakes are relatively rare.
The Tonga Meteorological Services said a tsunami warning was declared for all of the archipelago, and data from the Pacific tsunami centre said waves of 80 centimetres were detected.
Rachel Afeaki-Taumoepeau, who chairs the New Zealand Tonga Business Council, said she hoped the relatively low level of the tsunami waves would have allowed most people to get to safety, although she worried about those living on islands closest to the volcano.
She said she hadn’t yet been able to contact her friends and family in Tonga.
“We are praying that the damage is just to infrastructure and people were able to get to higher land,” she said.
US Secretary of State Antony Blinken wrote on Twitter he is “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 neighbours.”