The first humanitarian flights arrived in volcano and tsunami-stricken Tonga Thursday, five days after the dual disaster cut the Pacific nation off from the rest of the world.
Tonga has been inaccessible since Saturday, when one of the largest volcanic explosions in decades cloaked the kingdom in a layer of ash, triggered a Pacific-wide tsunami and severed vital undersea communication cables.
Officials said military transport planes from Australia and New Zealand touched down at Tonga's main airport - only recently cleared of a thick layer of ash after painstaking effort.
A "C-17 Globemaster left from Amberley Airport Base around 7:00 am today (2000 GMT)," an Australian defence official told AFP.
"The aircraft is carrying humanitarian aid and disaster relief supplies, including water containers, kits for temporary shelters, generators, hygiene and family kits, and communications equipment," New Zealand foreign minister Nanaia Mahuta said.
The first smattering of images to emerge from Tonga's capital Nuku'alofa show ashen buildings, toppled walls and streets littered with boulders, tree trunks and other debris.
More than 80 per cent of the archipelago's population of 100,000 have been impacted by the disaster, the United Nations has estimated, and initial assessments indicate an urgent need for drinking water.
Tongans worked for days at the airport trying to clear the runway of ash so that much-needed aid could arrive.
The work was painfully slow, with only a few hundred metres being cleared each day.
With the air bridge now open, nations are rushing to get aid in.
Japan has announced it will send two C-130 aircraft, and nations from China to France have indicated they will also provide assistance.
But strict Covid protocols that have kept Tonga virtually virus-free mean the delivery of supplies will be "contactless", with crews and passengers spending limited time on the ground.
'Unprecedented disaster'
Three people were killed when the Hunga Tonga-Hunga Ha'apai volcano exploded on Saturday, triggering tsunami waves that ripped down homes and caused widespread flooding.
The Tongan government has called the dual eruption-tsunami "an unprecedented disaster" and reported that waves as high as 15 metres (50 feet) destroyed almost every home on some outlying islands.
When the underwater caldera exploded, it fired debris 30 kilometres (19 miles) into the air and deposited ash and acid rain across the kingdom of 170 islands - poisoning water supplies.
"Water supplies across Tonga have been severely impacted by ashfall and saltwater from the tsunami," said Katie Greenwood of the International Federation of Red Cross and Red Crescent Societies.
She said there was a "mounting risk of diseases such as cholera and diarrhoea".
There are also fears for the island's food supplies, with a tearful national assembly speaker Fatafehi Fakafanua saying "all agriculture is ruined".
Cleared for landing
Australia and New Zealand are also sending help by sea, with Royal New Zealand Navy ships HMNZS Wellington and HMNZS Aotearoa expected to arrive in Tongan waters Friday.
They are carrying water supplies and a 70,000-litre-a-day desalination plant, as well as navy hydrographic and dive personnel to survey shipping channels.
Australian military relief ship the HMAS Adelaide is also standing by in Brisbane.
It is Canberra's "hope and intent" the ship will depart for the island kingdom Friday, an Australian official said.
HMAS Adelaide will carry "water purification equipment and additional humanitarian supplies," as well as two Chinook heavy-lift helicopters.
The eruption was one of the most potent in decades, releasing a pressure wave that traversed the planet, travelling at supersonic speeds of about 1,230 kilometres per hour, New Zealand's National Institute of Water and Atmospheric Research said.
It broke a vital undersea communications cable linking Tonga with the rest of the world and leaving Tongans overseas scrambling to contact loved ones.
While partial communications were restored Wednesday, mobile phone network provider Digicel said the high number of calls to the island was producing delays.
It is expected to be at least a month before the undersea cable connection is fully restored.