North Korea is clamping down on cell phones and long distance telephone calls to prevent the spread of news about a worsening food crisis, according to the United Nations investigator on human rights for the isolated communist country.

In a report to the U.N. General Assembly, Vitit Muntarbhorn, a Thai law professor who has never been allowed to visit North Korea, said that its government is using public executions as a means of intimidating the population, and using spies to infiltrate and expose religious communities.

His report came two days after the World Food Program said that two thirds of North Koreans do not have enough to eat, in the country’s worst crisis since as many as three million people died of famine a decade ago.

"Sadly, even though the harvest was getting better, we have had devastating floods in 2006 and 2007," Muntarbhorn said in New York. "Over the past year we have had very worrying information of a very chronic food shortage."

He acknowledged that the government of Kim Jong Il, North Korea’s supreme leader, has allowed access by international agencies to areas damaged by floods in 2007, but described the overall human rights situation as "grave."

"Particularly disconcerting is the use of public executions to intimidate the public," he said. "This is despite various law reforms in 2004 and 2005, which claim to have improved the criminal law framework and related sanctions."

Available food is disproportionately directed to the political elite, the media is controlled by the state, there is no political participation, and dissidents and those with religious faith are persecuted, as well as those who return to North Korea after illicitly leaving the country across the Chinese border.

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