In Letter to UN Secretary-General, Yad Vashem Chairman Avner Shalev Calls for Investigation of Political Genocide… In his letter, Shalev states with alarm that only six decades after the utilization of gas chambers to exterminate European Jewry, North Korea has apparently employed them against thousands of its own citizens… Shalev’s letter also reminds Anan of his speech on January 26 at the Stockholm International Forum, in which Anan said the world must do more to prevent genocide from ever taking place again…
See also here:
According to a BBC report aired Sunday, the North Korean government is also testing new chemical weapons on women and children… The BBC report quoted a former North Korean army intelligence officer who defected to South Korea in 1999, as saying that Prison Camp No. 22 had a gas chamber made of glass so scientists could observe inmates as they were gassed. “I witnessed a whole family being tested on suffocating gas and dying in the gas chamber,” he told the BBC. “The parents, son and a daughter.”
And see here for the campaign of human rights groups:
The U.S. and its partners should ensure that human rights abuses in North Korea – including startling new allegations of gas chamber experiments – are on the agenda at six-party nuclear talks scheduled for later this month, campaigners say.
While not optimistic that this will happen, groups campaigning for North Korean rights believe it is crucial that the Stalinist regime’s treatment of its citizens not be overlooked.