North Korea has begun to freeze ties with the South, which already halted most trade with Pyongyang in retaliation for the sinking of a South Korean warship. The North has denied responsibility for the attack on the vessel and is accusing the South of launching a "smear campaign" against it.
Pyongyang has expelled eight South Korean government officials from a joint factory park in the North. And, it is threatening to block what little cross-border traffic exists.
The Unification Ministry in Seoul says hundreds of South Korean managers and other workers from the South were allowed to enter the industrial complex in the west coast Kaesong border city, Wednesday.
But ministry spokesman Chun Hae Sung tells reporters North Korea quickly acted on other aspects of its threat to cut all communications ties with the South.
He says Pyongyang Wednesday halted contact between the Red Cross delegations in the truce village, Panmunjom, and the North Korean Navy contacted the South to inform it that all marine communications between the two Korea's are now cut.
Relations between the two Koreas have deteriorated steadily since the Cheonan, a South Korean naval vessel in the Yellow Sea, exploded a month ago, killing 46 crew members. An international investigation concluded last week that the coastal patrol warship was hit by a North Korean torpedo.
South Korea's defense ministry tells VOA News that plans to send tens of thousands of leaflets northward by ballon have been delayed because of wind conditions, but they could go aloft as early as Thursday. Officials say the leaflets are intended to inform North Koreans about the sinking of the South Korean naval vessel. The North views Southern pamphleteering as hostile propaganda.
South Korea's military is using loudspeakers along the border, silenced for six years, and re-instituting FM broadcasting to the North.
North Korea's state television newscaster announced such propaganda will not be tolerated.
The North Korean newscaster says it will open fire on the South Korean loudspeakers and destroy them.
Pyongyang says a resumption of the propaganda campaign will also compel it to totally shut down the Kaesong industrial complex, where more than 100 South Korean firms employ about 42,000 North Korean workers.
The two countries have no diplomatic relations and technically remain at war following a 1953 truce which ended the three-year Korean War.
The United States, which has 28,000 troops in South Korea, has hurriedly announced plans for several joint military exercises in the coming month. In the past, Pyongyang has strongly condemned U.S.-South Korean drills, claiming they are preparations for an invasion of the North.