CANBERRA, Australia — Aid flights from Australia, Japan and New Zealand carrying food, water, medical supplies and telecommunications equipment landed in Tonga over the weekend, as the Pacific nation grapples with the aftermath of an underwater volcanic eruption and tsunami.

The main airport runway has been cleared of ash spewed when the nearby Hunga Tonga Hunga Ha’apai volcano erupted a week ago. The explosion also set off a Pacific-wide tsunami that smashed boats in New Zealand and caused an oil spill as far as Peru.

“Obviously it’s a very, very difficult time for the people of Tonga. The feedback on the ground again I got today is many people displaced,” Australian Minister for International Development and the Pacific Zed Seselja told reporters in Canberra.

Cleanup efforts were going smoothly, with the Tongan government and military officials working together, he said.

Ships from the U.S. and Britain were on their way, he said. Also deployed was the HMAS Adelaide, an Australian navy ship, with helicopters on board as well as engineers and a 40-bed hospital. The ship can generate electricity and purify water.

A lack of clean water was a priority because supplies have been disrupted by layers of volcanic ash and salt water. Red Cross teams on the ground reported widespread stagnant pools of salt water that were dumped by the tsunami, polluting the clean drinking water sources of tens of thousands of people, said Katie Greenwood, the Pacific head for the International Federation of Red Cross and Red Crescent Societies.

On Saturday, the Japanese government said a Self-Defense Forces C-130 aircraft arrived in Tonga with three tons of drinking water. That followed a Japanese military flight on Friday. Another plane is scheduled to depart Sunday, carrying equipment for the ash cleanup, the Defense Ministry said.

Seselja said one bit of good news was that casualties have been relatively limited, with three deaths confirmed so far.

Three of Tonga’s smaller islands suffered serious damage from tsunami waves. The majority of Tongans live on the main island of Tongatapu, where about 50 homes were destroyed and coastlines strewn with debris.

U.N. humanitarian officials reported that about 84,000 people — 80% of Tonga’s population — have been impacted by the eruption.

The tsunami severed the single fiber-optic cable that connects Tonga to the rest of the world, leaving many unable to connect with loved ones abroad. Since then, satellite communication have improved and Tonga’s telecoms operator, Digicel, said it had been able to restore international call services to some areas.