Amnesty International has obtained new satellite images showing the growth of North Korea's largest prison complex — camps 15 and 16, or kwanliso — where prisoners are forced to dig their own graves, and women are raped then made to disappear. Amnesty explains in their most recent North Korea briefing the implications of the discovery:

Far from dismantling the political prison camps – places of systematic, widespread and grave human rights violations, such as forced hard labour, denial of detainee’s food quota as punishment, torture and other cruel, inhuman, or degrading treatment – they appear active and authorities appear to be investing in maintenance of the prisons’ infrastructure. 
Courtesy of Amnesty International
 
The organization also spoke with a former security guard, Mr Lee, who worked at camp 16 and discussed the horrifying treatment of the prisoners: 

Detainees were forced to dig their own graves and were then killed with hammer blows to their necks. He also witnessed prison officers strangling detainees and then beating them to death with wooden sticks. According to Mr Lee women were disappeared after being raped: “After a night of ‘servicing’ the officials, the women had to die because the secret could not get out. This happens at most of the political prison camps.”

One former prisoner witnessed the public execution of detainees who tried to escape: “They were brought to a stage after they were badly beaten. The prisoners were tied to wooden stakes and shot three times in their head, chest and feet," she said. 

Courtesy of Amnesty International

According to Amnesty International, among the hundreds of thousands held in North Korean prison camps are children and the families of alleged political criminals. North Korea officially denies the existence of such camps. 

In September, the United Nations published a report describing prison conditions in North Korea as comparable to those at Nazi concentration camps. The report was billed as part of an effort to propel possible criminal prosecution of North Korea's government —a task made difficult by the state's extreme secrecy and independence from the International Criminal Court.