North Korea warned on Monday of unpredictable disaster unless the South and the United States stop allowing tourists inside a heavily armed border buffer that is one of the most visited spots on the peninsula.

The warning comes as tensions were raised on the peninsula after a South Korean navy ship sank on Friday. Early reports that the North may have been involved spooked markets but were later played down when Seoul said it was almost certain Pyongyang had no part in the incident.

North Korea has made no mention of the ship-sinking incident in its official media.

An unnamed army spokesman of the North's Korean People's Army said South Korea was engaged in "deliberate acts to turn the DMZ into theatre of confrontation with the (North) and a site of psychological warfare" by allowing tours inside the border zone.

The Demilitarised Zone buffer is the 4-km wide buffer that runs along the military border drawn up under a truce that ended the 1950-53 Korean War, which was fought between U.S.-led U.N. forces with the South against North Korean and Chinese troops.

Tens of thousands of tourists a year visit the Panmunjom truce village inside the zone as well as other sites showing aspects of the Cold War's last frontier.

"If the U.S. and the South Korean authorities persist in their wrong acts to misuse the DMZ for the inter-Korean confrontation despite our warnings, these will entail unpredictable incidents including the loss of human lives," the North's KCNA news agency quoted the spokesman as saying.

The South's Korea Tourist Organisation said on its website ahead of the warning: "These days the DMZ is a safe destination that we would thoroughly recommend to any traveller."

Nearly half of the 104 crew members of the South's surveillance ship remained missing after the vessel sank Friday night after snapping in two apparently from a large explosion.

South Korean officials warned against premature conclusion on the cause of the incident until a thorough probe is conducted.


Reuters