Significant damage was reported along the western coast of Tonga’s main island of Tongatapu, where there are many vacation resorts, and the waterfront of the capital, Nuku’alofa. The Ha’atafu Beach Resort, 13 miles west of Nuku’alofa, was “completely wiped out”, the owners said on Facebook.

The UN Office for the Coordination of Humanitarian Affairs (OCHA) said there was “particular concern” about two small islands, Fonoi and Mango, where a distress signal was detected. According to the Tonga government, 36 people live on Mango and 69 on Fonoi.

“Further volcanic activity cannot be ruled out,” OCHA said, reporting only minor injuries but emphasising that formal assessments, especially of the outer islands, had yet to be determined.

New Zealand has been at the forefront of international aid efforts. On Tuesday, the country’s navy announced it had dispatched the HMNZS Wellington, carrying divers and hydrographers and a Seasprite helicopter. 

It said it would be joined by the HMNZS Aotearoa, loaded with much-needed water and humanitarian aid and disaster relief supplies.  

Alexander Matheou, the Red Cross’ Asia Pacific director, said water purification to remove ash contamination, providing shelter and reuniting families were the priorities in the aftermath of the disaster.