Authorities were searching Tonga's remote islands for cyclone victims Sunday after a powerful storm cut a swath of destruction through this South Pacific archipelago, killing one person and destroying most of the homes in some areas, AP reported. Relief efforts following Saturday's cyclone were concentrating on the Ha'apai islands - one of Tonga's three island groups between the main island of Tongatapu in the south and the Vava'u islands to the north, Tonga's Director of Emergencies Leveni Aho said. Cyclone Ian hit Tonga with gusts of up to 287 kilometers (178 miles) per hour. The storm was later downgraded from Category 5 - the most destructive level - to Category 4, with gusts of up to 250 kph (155 mph). On Sunday, the cyclone was tracking southeast away from Tonga. Tonga is an archipelago of 176 islands, 36 of which are inhabited by more than 100,000 people. Its economy relies on fish exports, tourism and remittances from Tongan communities overseas, with about 40 percent of the population living in poverty.