North Korea has accused South Korea’s military of firing more than 10 warning shots at a group of North Korean soldiers working on a border-fortification project on 19 August. Vice Chief of the General Staff Ko Jong-chol said the rounds, allegedly discharged from a 12.7-millimetre machine gun, amounted to a "premeditated and deliberate" provocation intended to incite conflict. In a statement carried by the official Korean Central News Agency, Ko warned that any further interference with what Pyongyang calls a permanent barrier project near the Military Demarcation Line would draw "corresponding countermeasures." North Korea said it had notified US forces in South Korea of the construction activity in June and July to avoid accidental clashes. The complaint comes as South Korea and the United States conduct their annual Ulchi Freedom Shield exercises, an 11-day training programme that Pyongyang routinely denounces as a rehearsal for invasion. South Korea’s Joint Chiefs of Staff have not publicly confirmed the North’s version of events but have previously acknowledged broadcasting warnings and firing shots when Northern troops cross the boundary.