▁has ▁often ▁threatened ▁its ▁Southern ▁counter part . ▁From ▁ 1 9 5 4 , ▁North ▁Korea ▁has ▁been ▁b oring ▁t unn els ▁to ▁the ▁South . ▁Up ▁until ▁ 1 9 9 0 s ▁only ▁four ▁of ▁them ▁have ▁been ▁found ▁by ▁the ▁South , ▁but ▁civil ian ▁tunnel ▁dig gers ▁( 남 굴 사 ) ▁claim ▁that ▁there ▁are ▁other ▁networks ▁of ▁t unn els ▁under ▁the ▁South . ▁ ▁There ▁are ▁reports ▁that ▁the ▁North ▁has ▁export ed ▁their ▁skill ▁of ▁b oring ▁t unn els ▁to ▁He z bol lah ▁in ▁Leb anon ▁and ▁Ham as ▁in ▁the ▁Gaz a ▁strip . ▁Swedish ▁journalist ▁Bert ie ▁L int ner ▁has ▁provided ▁pictures ▁of ▁North ▁Kore ans ▁helping ▁the ▁tunnel ▁b oring ▁in ▁My an mar . ▁He ▁is ▁considered ▁to ▁be ▁the ▁first ▁journalist ▁to ▁reve al ▁the ▁growing ▁relationship ▁between ▁My an mar ▁and ▁North ▁Korea ▁on ▁strateg ic ▁co operation . ▁L int ner ▁has ▁stated ▁that ▁in ▁the ▁ 1 9 7 0 s , ▁Sweden ▁export ed ▁T B M s ▁of ▁Atlas ▁Cop co ▁Cor p . ▁to ▁North ▁Korea . ▁ ▁Four ▁t unn els ▁have ▁been ▁discovered . ▁The ▁first ▁tunnel ▁( 제 1 땅 굴 ), ▁was ▁found ▁in ▁ 1 9 7 4 ▁in ▁J ang nam My un ▁Ye on Che on K un , ▁Ky ung ki ▁Province , ▁and ▁the ▁second ▁tunnel ▁( 제 2 땅 굴 ) ▁was ▁found ▁in ▁ 1 9 7 5