The man was first spotted crossing the barbed wire fence at around 7:30 p.m. Tuesday night, according to local media, and was then found about 10 a.m. the next morning on the eastern side of the demilitarized zone that divides the careers.

That's according to the South Joint Chiefs of Staff, who said in a statement that an investigation is being planned.

It comes as South Korea resumed tours to the southern part of the demilitarized zone on Wednesday after the tours were put on pause in October last year after an outbreak of the deadly African swine fever in the north.

However, Unification Minister Lee in Young made no mention off the North Korean man when celebrating the two of restart.

Lee called for restoring relations with the North and the recovery off inter Korean hotlines that were severed back in June.