SEOUL, South Korea -- North Korea said Wednesday that it had cut off a key military hotline with South Korea that allows cross border travel to a jointly run industrial complex in the North, a move that ratchets up already high tension and possibly jeopardizes the last major symbol of inter-Korean cooperation.
North Korea recently cut a Red Cross hotline with South Korean and another with the U.S.-led U.N. command at the border between the Koreas, but there's still a hotline linking aviation authorities in the North and South.
North Korea's chief delegate to inter-Korean military made the announcement Wednesday in a statement sent to his South Korean counterpart. The hotline is important because the Koreas use it to communicate as hundreds of workers travel back and forth to the Kaesong industrial complex.
South Korean officials say more than 900 South Korean workers were in Kaesong on Wednesday. There was no immediate word about how cutting the communications link would affect their travel back to South Korea.
North Korea, angry over routine U.S.-South Korean drills and recent U.N. sanctions punishing it for its Feb. 12 nuclear test, has unleashed a torrent of threats recently, including vows to launch a nuclear strike against the United States. It has also repeated its nearly two-decade-old threat to reduce Seoul to a "sea of fire."
Despite the rhetoric, outside weapons analysts have seen no proof that North Korea has mastered the technology needed to build a warhead small enough to mount on a missile.
Still, the cutting of the hotline could be more significant if it affects travel by the workers at Kaesong.
Kaesong is operated in North Korea with South Korean money and know-how and a mostly North Korean workforce. It provides a badly needed flow of hard currency to a country where many face food shortages.
The complex is the only remaining operational symbol of joint inter-Korean cooperation.
In March 2009, North Korea cut off the military hotline with South Korea and kept 80 South Korean workers stranded in Kaesong for a day. The cross-border travel resumed after North Korean authorities approved it through a South Korean office in Kaesong. The military hotline remained cut off for more than a week and was reconnected following the end of annual South Korean-U.S. military drills.