The Joint Chiefs of Staff (JCS) in Seoul is rejecting North Korea’s claim that South Korean troops fired artillery shots in the demilitarized zone (DMZ) on Sunday.

The JCS says South and North Korean guards were seen approaching the DMZ on Sunday upon hearing what was thought to be an explosion but that no shots were fired.

The JCS said old land mines could have exploded.

The North's Korean Central Television, however, reported that the South Korean military fired 90-millimeter artillery shots from south of the military demarcation line within the DMZ toward a North Korean guard post around 2:07 p.m. Sunday.

The station said North Korean security was seriously threatened, and it called for the punishment of those responsible.