Floods triggered by tropical storm Nock-Ten have killed at least 20 people in northern Thailand and damaged more than 99,000 hectares of farmland, reports said Sunday. The department of disaster prevention and mitigation designated 20 northern and north-eastern provinces as flood disaster zones after more than a week of heavy rain, the Bangkok Post reported. It said seven flood-related deaths were recorded in Mae Hong Son and two in Chiang Mai, both northern provinces popular with Western tourists. Floods have affected more than 1 million people, and damaged 619,723 rai (99,155 hectares) of farmland.