Official says there is an immediate need for drinking water and food, as efforts begin to assess the scale of the damage.

Tonga is calling for “immediate aid”, with an urgent need for fresh water and food, as it assesses the damage caused by Saturday’s eruption of Hunga-Tonga-Hunga-Ha’apai.

The volcano exploded in a massive eruption on Saturday – said to be the biggest since Pinatubo in the Philippines in 1991 – triggering a tsunami and blanketing the Pacific island nation in volcanic ash.

“Communications remain down and the full extent of the harm to lives and property is currently unknown. What we do know is that Tonga needs immediate assistance to provide its citizens with fresh drinking water and food,” Parliament Speaker Lord Fakafanua said in a statement shared on social media.

The appeal came as experts detected another eruption at Hunga-Tonga-Hunga-Ha’apai.

The Darwin Volcanic Ash Advisory Centre said the volcano erupted at 22:10 GMT on Sunday, with the Pacific Tsunami Warning Centre saying it had detected large waves in the area: “This might be from another explosion of Tonga volcano. There are no known earthquakes of significant size to generate this wave.”

Australia and New Zealand on Monday sent surveillance flights to assess the damage in Tonga and said they were coordinating with the United States, France and other countries on the humanitarian response.

Our P3 Orion has been dispatched to Tonga to support the assessment of the extent of damage caused to Tongatapu and outer islands. This is a significant event and NZ🇳🇿 will do all it can to offer its support and assistance. Our thoughts and prayers are with the people of Tonga 🇹🇴

— Nanaia Mahuta (@NanaiaMahuta) January 16, 2022

Australia’s Minister for the Pacific, Zed Seselja, said initial reports suggested there had been no mass casualties and that the airport “appears to be in relatively good condition”, but there was “significant damage” to roads and bridges.

The Red Cross has offered its assistance and the Pacific Islands Forum said it was ready to assist in what it described as a “once in a millennium natural disaster”.

“In the coming hours and days we will get a clearer picture of the situation in Tonga, as well as the rest of the Blue Pacific Continent,” Secretary General Henry Puna said in a statement.

The effect of Saturday’s eruption was felt across the Pacific, in other island nations such as Fiji, where video shared on social media recorded the explosive sound of the eruption, and in North and South America. A vast cloud of ash is now spreading westwards towards Australia.