President Lee Myung-bak has condemned the killing of a South Korean tourist by a soldier in North Korea and called on Pyongyang to fully cooperate in investigating the shooting.
Park Wang-ja, a 53-year-old housewife from Seoul, was taking an early morning stroll to watch the sunrise at the Mount Kumgang holiday resort in North Korea on Friday when she apparently strayed into a military zone and was shot dead.
She is the first South Korean tourist to be killed by a North Korean, a government official said on Saturday.
"Something that must not happen has happened," Mr Lee said at an emergency cabinet meeting attended by the ministers of defence, foreign affairs, unification and the head of South Korea's spy agency.
"It is beyond anybody's understanding that an unarmed civilian tourist was shot and killed," he was quoted as saying by Yonhap news agency.
Mr Lee said North Korea must "actively cooperate" in finding the truth about the killing.
The incident comes as ties between the states, technically still at war, chilled in recent months and Mr Lee, who has advocated taking a tough line with Pyongyang, repeated calls for dialogue.
South Korea is conducting an investigation and looking into North Korean claims that a sentry shouted at Ms Park to halt, and fired a warning shot before shooting.
Medical authorities said Ms Pak was shot once in the chest and once in her buttocks.
A South Korean Unification Ministry official said North Korea has shown little interest in cooperating with the investigation.
South Korea has now suspended tourism to the Mount Kumgang resort, a few kilometres north of the heavily fortified border on the east coast.
The South Korean affiliate of the Hyundai Group that runs the resort has been shuttling tourists back to the South since Friday.