North Korea says tidal waves up to four metres high hit the southeastern province of Kangwon earlier this week flooding thousands of hectares of farmland and causing extensive damage.

The official North Korean news agency said crops had been destroyed along with roads and irrigation channels and the flooding would make it impossible to distribute food in June and July.

The international community has sent food aid to North Korea to avert a famine, but the United Nations says malnutrition and disease remain endemic, especially among children.