Man killed crossing Korea borders
Soldiers opened fire after the man jumped into the Imjin river and ignored repeated warnings to stop.
The North and South remain technically at war after the 1950-53 conflict ended in an armistice and not a peace treaty.
There are thousands of North Korean defectors living in South Korea, but few attempt to make the journey the other way.
Instances of people trying to cross the heavily-militarised border in broad daylight are extremely rare.
The incident comes as South Korean workers returned to the Kaesong industrial park in North Korea, five months after work was halted amid high political tension.
The man was spotted by guards near the western border in Paju, north of Seoul, at around 14:20 local time.
Soldiers fired off warning shots and told him to return to the South. When he disobeyed the order and jumped into the river, he was shot dead by an army corporal, military officials told Yonhap news agency.
Defence ministry officials told the Associated Press that the man was carrying a South Korean passport which identified him as Nam Young-ho. He had been deported from Japan in June, the agency reported.
The BBC’s correspondent in Seoul, Lucy Williamson, says the incident occurred close to the the Imjingak Memorial Park – a key tourist site along the demilitarised zone between the North and the South.
The shooting comes amid a thawing of ties between the North and the South as more than 800 South Koreans poured into the jointly-run Kaesong industrial complex.
The zone, just inside North Korea, is home to 123 South Korean factories that employ more than 50,000 North Koreans.
It is the last functioning inter-Korean joint project and a key source of revenue for Pyongyang.
But the North withdrew all of its workers in April, as ties between the two Koreas deteriorated in the wake of Pyongyang’s 12 February nuclear test.
Reopening the complex has taken months of negotiation. (BBC)