Ammunitions factories in North Korea are concentrated in Jagang Province, bordering China, and are mostly constructed underground, so while working, the munitions workers are unable to get any sunlight. ‘Factory No. 26,’ located in Kanggye City, Jagang Province, though camouflaged as a tractor parts maker, turns out missiles and shells. ‘Factory No. 38’ in Huichon of the same province, though called the ‘Combined Youth Electric Business Establishment,’ also manufactures missiles

The munitions laborers reportedly enjoy preferential treatment and prior to the food shortages, a male worker was supplied with 800g of rice per day, edible oil and meat, among other foods, plus clothing and shoes. Even after the food crisis set in, all of them reported to work in sharp contrast with many of their counterparts in other industries who, because of suspended food rations, absented themselves from jobs, according to North Korean defectors in the South. “When food rations were halted for the munitions workers as well, some of them saved and took home one of three meals given them at factory canteens each day," said one of them. "This practice resulted in ceaseless arguments between them and guards." Even in the face of the economic woes, munitions factories continued operating, while ordinary plants suspended their operations.

Yi Jong-hui, 25 (pseudonym), a North Korean escapee here, was assigned to ‘Munitions Factory No. 24,’ a producer of automatic rifles, in the province's Jonchon county upon graduation from a senior high school. "When I entered the plant I stamped all ten fingers on a written pledge to not reveal any secrets of the work, and accepting any possible punishment in the event of a breach of the pledge," she recalled. "Senior female workers told us recruits that we have to continue working for the plant even after marriage, and that we have to find our spouses from among our male counterparts of the factory. That meant that once we were in, we could not ever get out."

The factory is composed of over 100 tunnels, each of which is identified as a job site with a serial number, according to Yi. About a dozen teams, comprising 45-50 laborers, work in each of the job sites, which are divided mainly by rifle parts such as muzzle, butt, firing rod, barrel and magazine.

Yi, who belonged to an assembly team, estimated the factory's capacity at about 1,000 rifles per day. Inspectors determine whether produced rifles meet required quality by test-firing some of them at a firing range available near the factory.

Security rules are so tight that workers are allowed no access to adjacent tunnels and even managers are subject to severe control in movements. To reach a job site, one has to walk down a tunnel for about 15 minutes. The area around tunnel entrances is encircled by electrically charged barbed wire. The first gate is made of steel and the second one of rock. Workers have to go through three checkpoints manned by armed state security agents. Each time they must show their passes. One whose pass has even scratches on it is rejected entry. As they are more than 100 meters below ground level, the work sites are cool in the summer and warm during the winter.

As of 1996 North Korea had 134 munitions factories - among them 35 producing ammunition; five, tanks and armored vehicles; five, naval vessels; nine, airplanes; three, missiles and guided weapons; five, communications equipment; and eight biochemical weapons. Some ordinary factories are ready to be converted into ammunition works in times of war.