Kim Chang Sok, department director of the ministry, told KCNA:

Coal mining complexes across the country are boosting the production by giving precedence to tunneling and through rational mining methods.

Coal mines under the Sunchon Area Youth Coal Mining Complex are overfulfilling their capital tunneling assignments every day.

The Tukjang, Kaechon and Myongchon area coal mining complexes are directing efforts to slope pit tunneling for deep mining and increasing more coal than planned.

The Tokchon, Pukchang and other area coal mining complexes have introduced tunneling methods suited to the coal-bed conditions to overfulfill their daily quotas.