North Korea has clamped down on fast-growing free markets for fear they could undermine the communist state's power over its people, analysts and observers say. The regime in late November banned general markets which sell consumer goods from early next year. It severely restricted the operations of food stalls, according to the Daily NK web newspaper and other analysts. [...] Staples such as rice and corn will be sold only at state distribution centres. [...] Kim Yong-Hyun, a North Korea studies professor at Dongguk University, said the state is trying to reassert control over distribution because sharp price rises have put basic commodities beyond the reach of ordinary people. [...] North Korea may have to ease the clampdown because it cannot solve food shortages and state stores do not have enough products to sell, he said. Chronic food shortages worsened this year, the Food and Agriculture Organisation and the World Food Programme said in a joint report last week. About 40 percent of the population -- an estimated 8.7 million people -- will urgently need food aid in coming months, they said.