South Korean border guards fired warning shots as about 10 North Korean soldiers approached the military demarcation line (MDL) inside the demilitaized zone (DMZ), Seoul's military officials said, adding that there was no exchange of fire.

 An official at Seoul's Joint Chiefs of Staff (JCS) said the North Korean soldiers stayed around their side of the MDL in Cheorwon, Gangwon Province, about 88 kilometers north of the capital city, from 8:30 a.m. to 4 p.m. Saturday. The North Koreans neither crossed the MDL nor responded to the warning shots, he said.

South Korean guards fired warning shots after broadcasting warning messages in accordance with their military's standing operating manuals, the official said.

"The soldiers came down to read the MDL markers on the northern side of the border," the official said. "Our military acted in accordance with guidelines on how to respond when North Koreans come toward the MDL, and fired warning shots and aired warning messages on three occasions."

The official said North Korean soldiers occasionally approach the MDL without actually crossing it, and this has happened "a few times" this year.

The two Koreas are sensitive to border incidents. They are still technically at war with the 1950-53 Korean War ending in an uneasy armistice, not in a permanent peace treaty.

Last week, the two Koreas exchanged gunfire twice across their maritime and land border. (Yonhap)