South Korea's military launched a massive hunt for North Korean infiltrators yesterday after the body of a suspected commando was washed ashore.
Troops were put on high alert after the armed corpse was found on a beach in the eastern port city of Donghae, along with spy equipment, the Defence Ministry said.
Soldiers combed the coast and nearby mountains for traces of other infiltrators, it said, while police road blocks on highways in the Seoul area checked motorists.
The body was found near where a North Korean spy submarine was captured last month. The submarine's nine-man crew were all found dead. But officials said the latest corpse came from a separate mission.
"We believe the body must be that of an armed North Korean commando who had drowned while trying to land" in a rainstorm, Mr Kang Jun-Kwon, a ministry spokesman, said. "Medical officers suggested the man died within the 48 hours before he was found."
The military also discovered a propeller-driven undersea vehicle, goggles, and a sack containing a Czech-made automatic rifle, a rectangular grenade used by North Korean troops, a knife and a radio transmitter.
"Such belongings strongly indicate the dead man was on a spy mission. The propeller-driven vehicle can carry up to five people. So we cannot rule out the possibility of other commandos," Mr Kang said.
President Kim Dae-Jung called for heightened military vigilance and expressed concern over the North's infiltration attempts, an aide said.
The Deputy Unification Minister, Mr Chung Se-Hyong, warned that the incident could dampen Seoul's attempts to ease tension with the North. "We feel sorry that this kind of incident occurs amid our efforts to improve inter-Korean relations," Mr Chung said. The joint chiefs of staff commander, Gen Kim Jin-Ho, put troops on "top alert" along the eastern border, raising the possibility that armed North Korean agents could have already come ashore.
Television showed trucks packed with troops moving around the city, some 100 km south of the demilitarised zone (DMZ) which divides the two Koreas.
The bodies of nine North Koreans with bullet wounds were found inside the submarine after last month's intrusion and later handed over North Korea. The North denied the submarine was on a spy mission. But Seoul has demanded an apology, calling the intrusion a "serious aggression".
The submarine became entangled in fishing nets near where 26 armed commandos ran aground in a North Korean midget submarine in 1996.