N. Korea's Kwanliso 16 prison camp growing, Amnesty International says LONDON, Dec. 5 (UPI) -- A North Korean facility described as a political prison camp is growing and should be investigated, the human rights group Amnesty International said Thursday. The organization, headquartered in London, said in a statement new buildings and an expansion of production facilities have been observed in satellite photos of the Kwanliso 16 camp, near Hwaseong, North Korea. The images, taken in May, show an increase in the camp's population, with new housing constructed and under construction, it said. Amnesty International noted the 560-square kilometer (216-square mile) camp is among the least investigated prison camps in the world, with an estimated 20,000 people imprisoned there. The statement added forced hard labor is common in North Korean prison camps, and that Amnesty International is sharing its latest analysis with a United Nations Commission of Inquiry investigating human rights abuses in North Korea.