Tonga devastated by volcanic eruption, tsunami — in pictures

Tonga officials confirmed that at least three people died after a massive undersea volcanic eruption and tsunami hit the Pacific nation — what the government called an "unprecedented disaster." With the country's only internet cable cut, it remains difficult to understand the extent of the damage through patchy satellite phone connections, surveillance flights and satellite images.

Volcanic ash has blanketed Tonga, as seen in this before-and-after image. World Health Organization official Sean Casey said that "the whole country is covered in ash," adding that water contamination is currently the biggest threat to the population. The UN health agency said around 100 houses had been damaged, with 50 destroyed on Tonga's main island of Tongatapu.

The Hunga Tonga-Hunga Ha'apai underwater volcano had erupted on Saturday, sending ash some 30 kilometers (19 miles) into the air. It deposited ash, gas and acid rain across a large area of the Pacific. A tsunami followed the volcano, raising waves in Tonga up to 15 meters (50 feet), its government said.

As communication from Tonga remained severed, New Zealand sent surveillance flights to survey the damage. Several international organizations, including the UN and Red Cross, are trying to send aid, but Tonga's airport remains closed. Australia and New Zealand said they would send ships with aid — which could take days due to the massive distance.

Large waves from the volcanic eruption are believed to have caused an oil spill in an area rich in marine biodiversity in Peru. Peruvian authorities said that a ship was loading oil into a refinery on the Pacific coast on Sunday when strong waves moved the boat and caused the spill. So far, it is the only known oil spill to have have occurred in the Pacific basin after Saturday's eruption.

Tsunami waves caused by the eruption spread across the Pacific Ocean and hit Japan's coastline. Rafts of farmed oysters in Japan's eastern Mie Prefecture were carried out to sea by the waves.

The impact was felt in New Zealand as well. Waves that swept into marinas severely damaged boats, while others in New Zealand said they could hear the eruption.

An eruption in 2015, pictured above, caused the formation of a volcanic cone between the islands of Hunga Tonga and Hunga Ha'apai. The eruption released dense, particle-rich jets.