(Reuters) -The United Nations is preparing to carry out relief operations for Tonga at a distance to avoid a COVID-19 outbreak in the Pacific island nation reeling from a volcanic eruption and tsunami, an official said on Wednesday.Eruption of the underwater volcano Hunga Tonga-Hunga Ha'apai off Tonga© Reuters/TONGA GEOLOGICAL SERVICES Eruption of the underwater volcano Hunga Tonga-Hunga Ha’apai off TongaAll the homes on one of Tonga’s small outer islands have been destroyed and three people have died, the government said in its first statement https://www.reuters.com/world/significant-damage-reported-tongas-main-island-after-volcanic-eruption-2022-01-17 after Saturday’s devastating eruption which it called “an unprecedented disaster”.

A general view from a New Zealand Defence Force P-3K2 Orion surveillance flight shows heavy ash fall over Nomuka in Tonga© Reuters/NEW ZEALAND DEFENCE FORCE A general view from a New Zealand Defence Force P-3K2 Orion surveillance flight shows heavy ash fall over Nomuka in TongaWith communications https://www.reuters.com/markets/funds/undersea-cable-fault-could-cut-off-tonga-rest-world-weeks-2022-01-18 badly hampered by the severing of an undersea cable, information on the scale of the devastation so far has mostly come from reconnaissance aircraft.

Fiji-based United Nations co-ordinator Jonathan Veitch said in a media briefing that the agency will conduct most operations remotely, and may not send personnel to the island.

“We believe that we will be able to send flights with supplies. We’re not sure that we can send flights with personnel and the reason for this is that Tonga has a very strict COVID-free policy,” Veitch said.

Tonga is one of the few countries that is COVID-19 free and an outbreak there would disastrous, he said. The tiny island nation has 90% immunisation coverage both in adults and also younger people over the age of 12, Veitch said.

“They’ve been very cautious about opening their borders like many Pacific islands, and that’s because of the history of disease outbreaks in the Pacific which has wiped out societies here.”

The U.N. has 23 people on the ground plus other international NGOs to help with relief efforts, Veitch said.

He said the World Health Organization would start a discussion with the government “in a cautious manner, but we won’t be doing anything to threaten the safety of their protocols and the safety of their population in terms of COVID.”

James Garvin, chief scientist at NASA’s Goddard Space Flight Center, said the force of the eruption was estimated to be equivalent to five to 10 megatons of TNT, an explosive force more than 500 times the nuclear bomb dropped by the United States on Hiroshima, Japan, at the end of World War Two.

CLEAN UP UNDERWAY

The Tongan government has started evacuating stranded residents in some outlying areas. Water supply has been “seriously affected” by volcanic ash and is a major concern, the prime minister’s office said in its statement late on Tuesday.

Tonga is expected to issue formal requests for aid soon but in the meantime New Zealand and Australian ships have set off with water supplies, survey teams and helicopters.

Australian Prime Minister Scott Morrison said at a news conference in Canberra that he hoped to speak with Tonga Prime Minister Siaosi Sovaleni later on Wednesday.

“It is a very difficult environment to be operating in, the ash clouds and things of that nature. Our defence forces have stood up their operation and are deploying as necessary, as directed,” Morrison said.

The island is still largely offline after the volcano took out the sole undersea fire-optics communication cable, which may take weeks to repair.

Limited communications had been established through satellite phones and other means in Tongatapu, but the outlying areas remained cut off.

Tongan communities abroad posted new images received from families back home on Facebook, giving a glimpse into the extent of the devastation.

The images show homes reduced to rubble, fallen trees, cracked roads and sidewalks and ash from the volcanic eruption spread across the entire island.

Clearing the airport runway of ash is a priority for the government. The archipelago’s main Fua’amotu International Airport was not damaged but the ash was having to be manually removed.

“We thought that it would be operational yesterday, but it hasn’t been fully cleared yet because more ash has been falling,” U.N.’s Veitch said.

Tsunami waves reaching up to 15 metres hit the Ha’apia island group, where Mango is located, and the west coast of Tonga’s main island, Tongatapu, the prime minister’s office said. Residents were being moved to evacuation centres as 56 houses were destroyed or seriously damaged on that coast.

Atata and Mango are between about 50 km and 70 km from the Hunga Tonga-Hunga Ha’apai volcano https://graphics.reuters.com/TONGA-VOLCANO/znvneloakpl, which sent tsunami waves across the Pacific Ocean when it erupted with a blast heard 2,300 km (1,430 miles) away in New Zealand.

Australia and New Zealand have promised immediate financial assistance to Tonga.

The U.S. Agency for International Development approved $100,000 in immediate assistance to support people affected by volcanic eruptions and tsunami waves.

(Reporting by Michelle Nichols, Kirsty Needham and Tom Westbrook; writing by Praveen Menon; editing by Grant McCool)