About 130 North Korean officials visited the tense frontier with South Korea last week as Pyongyang intensified its threats against Seoul, a report said Wednesday.
The North's Defence Minister Kim Yong-Chun and military chief Ri Yong-Ho toured the border truce village of Panmunjom on March 4, Yonhap news agency quoted an unidentified South Korean military official as saying.
The official also said mid-level officials had since travelled to the village and vehicles carrying oil, food and other supplies were sighted in the area.
US and South Korean military officials had no comment on the report.
The communist country's new leader Kim Jong-Un on March 3 made a surprise inspection visit to the village, which straddles the border, and placed troops there on alert.
Kim has made a series of trips to frontline military units since the death of his father Kim Jong-Il on December 17.