The first flights carrying fresh water and other aid to Tonga have finally arrived after the Pacific nation’s main airport runway was cleared of ash left by a huge volcanic eruption.

New Zealand and Australia each sent military transport planes that were carrying water containers, kits for temporary shelters, generators, hygiene supplies and communications equipment.

The Australian plane also had a special sweeper to help keep the runway clear.

The deliveries were dropped off without the military personnel coming in contact with people at the airport in Tonga.

That is because Tonga is desperate to make sure foreigners do not bring in the coronavirus. It has not had any outbreaks of Covid-19 and has reported just a single case since the pandemic began.

“This assistance will help our partners, the Tongan government, meet the Tongan community’s needs and support immediate clean-up efforts,” Australian foreign affairs minister Marise Payne said. “Many homes have been destroyed and many people displaced by the tsunami.”

Japan also said it would send emergency relief, including drinking water and equipment for cleaning away volcanic ash. Two Hercules aircraft and a transport vessel carrying two CH-47 Chinook helicopters would leave possibly on Thursday, the Defence Ministry said.

Defence minister Nobuo Kishi told reporters that his ministry “will do everything we can for the disaster-hit people of Tonga”.

UN humanitarian officials report that about 84,000 people — more than 80% of Tonga’s population — have been affected by the volcano’s eruption, UN spokesman Stephane Dujarric said, pointing to three deaths, injuries, loss of homes and polluted water.

Communications with Tonga remain limited after Saturday’s eruption and tsunami appeared to have broken the single fibre-optic cable that connects Tonga with the rest of the world.

That means most people have not been able to use the internet or make phone calls abroad, although some local phone networks are still working.

One phone company, Digicel, said on Thursday it had managed to restore the ability to make international calls from some places by using a satellite link, but that people would need to be patient due to high demand. It said it hoped to enhance its service over the coming days.

A navy patrol ship from New Zealand is also expected to arrive later on Thursday. It is carrying hydrographic equipment and divers, and also has a helicopter to assist with delivering supplies.

Officials said the ship’s first task would be to check shipping channels and the structural integrity of the wharf in the capital, Nuku’alofa, following the eruption and tsunami.

Another New Zealand navy ship carrying 250,000 litres of water is on its way. The ship can also produce tens of thousands of litres of fresh water each day using a desalination plant.

Three of Tonga’s smaller islands suffered serious damage from tsunami waves, officials and the Red Cross said.

Mr Dujarric said “all houses have apparently been destroyed on the island of Mango and only two houses remain on Fonoifua island, with extensive damage reported on Nomuka”. He said evacuations are under way for people from the islands.

According to Tongan census figures, Mango is home to 36 people, Fonoifua is home to 69 people, and Nomuka to 239. The majority of Tongans live on the main island of Tongatapu, where about 50 homes were destroyed.

Mr Dujarric said the most pressing humanitarian needs are safe water, food and non-food items, and top priorities are re-establishing communication services including for international calls and the internet.