Authorities are searching remote islands for cyclone victims after the most powerful storm to hit Tonga in decades tore through the South Pacific archipelago, flattening homes and leaving at least one person dead.
Relief efforts on Sunday were concentrating on the Ha'apai islands, between the main island of Tongatapu in the south and the Vava'u islands to the north, said Leveni Aho, Tonga's director of emergencies.
Authorities had been unable to make telephone contact with 23 islands that account for most of the inhabited islands in the Ha'apai group, Aho said.
"The patrol boats are still out there, going from island to island to scout for information," he said.
Ha'apai governor Tu'i Ha'angana said he could see from one side of the island to the other, and "that's how devastated it is".
Cyclone Ian hit Tonga with gusts of up to 287km per hour on Saturday, putting it in category five, the most severe type of cyclone. It was later downgraded to category four, and on Sunday the storm was tracking southeast away from Tonga.
Two navy patrol boats carrying tarpaulins, tents and other emergency supplies had left Tongatapu to bring help to victims who were cut off in the Ha'apai islands.
The islands are home to 8,000 people, most of whom live on the devastated islands of Lifuka, where one person died, and Foa.
Aho estimated that hundreds of people on the two islands were taking shelter in church buildings being used as evacuation centres. Up to 70 percent of the homes and buildings in some areas had been flattened, officials said.
Tupou Ahomee Faupula, from Tonga's mobile phone provider Digicel, said his field officer in Ha'apai, Uaisele Fonokalafi, reported widespread devastation: "He told us that this was the worst ever damage from a cyclone. Most houses are flattened, roofs are off, trees and power lines are down."