Shots fired at DMZ as another N.Korean soldier defects to South

People look toward the north through a barbed-wire fence near the militarized zone separating the two Koreas, in Paju, South Korea, December 21, 2017. REUTERS/Kim Hong-Ji

SEOUL (Reuters) - South Korean guards fired warning shots across the heavily militarized border with North Korea on Thursday as a soldier from the North defected in thick fog, complicating efforts to ease tensions over Pyongyang's nuclear and missile programmes.

A South Korean defence ministry official said up to 20 warning shots were fired as North Korean troops approached too near the "military demarcation line" at the demilitarized zone (DMZ), apparently in search of the missing soldier.