NK soldiers cross border prompting warning shots

North Korean soldiers briefly crossed the demilitarised zone (DMZ) on Tuesday, South Korea has said, ahead of a rare state visit to Pyongyang by Russian President Vladimir Putin.

The soldiers retreated after the South Korean military fired warning shots, but Seoul believes their violation of the border was not intentional.

South Korea said it believed the soldiers accidentally crossed as they were fortifying the border, the second such incident in over a week. The border itself is not fenced and the signposts are obscured by heavy growth of vegetation.

"20 to 30 soldiers came about 20 meters below the military demarcation line (MDL) inside the demilitarized zone (DMZ)," South Korea's Joint Chiefs of Staff (JCS) said in a statement.

It's the second crossing incident in two weeks, with Seoul saying North Korean troops crossed into South Korea on 9 June with tools, including pickaxes. They retreated when South Korean reacted with loudspeaker warnings and warning shots.