SEOUL, Nov. 12 (UPI) -- North Korea's largest political prison camp is expanding its operations, according to the most recent images of the penal labor colony.
Using Google Earth satellite imagery, Curtis Melvin of the U.S.-Korea Institute at Johns Hopkins University, told Radio Free Asia that the aerial snapshots from Oct. 15 indicated considerable changes have been made to Camp No. 16.
Melvin said the new changes included dams, hydroelectric power plants, apartments for the camp's guards, an athletic field, a mine and fish farms. These facilities were not visible in satellite imagery taken in 2013.
The latest construction appears to indicate that North Korea is planning for an increase in the population of inmates detained at Camp No. 16, which according to Yonhap, is half the area of Pyongyang, the country's capital. In 2014, Amnesty International said in a statement the camp imprisons about 20,000 people and the prisoners are forced to work in very treacherous conditions.
In total, North Korea operates five political prison camps where the state keeps 80,000 to 120,000 prisoners for "crimes against the state."
Pyongyang has repeatedly denied the existence of the camps and has accused defectors who survived life in the penal colonies of lying in their testimonies to the United Nations and the foreign press.
North Korea has been wary of analysts who find ways to study the regime and its shadowy practices. Melvin, who has conducted analyses for other developments in the country, said Pyongyang's state media website KCNA had planted malicious codes in a mandatory "Flash Update" download that appears when visitors open the site, Radio Free Asia reported Nov. 7.
Melvin said he confirmed through a security program the download was an attempt to hack into the personal computers of visitors, and that the attack's point of origin could be traced to a North Korean IP address.
South Korean newspaper Chosun Ilbo reported the attempt to push malicious codes onto a Flash Player to invade computer systems is not the first time North Korea has tried infiltrating unsuspecting users of its website.