North Korea on Monday fired several artillery rounds toward a disputed maritime border with South Korea in the Yellow Sea, the Yonhap news agency reported.
It said Pyongyang had warned of "strong physical retaliation" against the drills that it denounced as preparations for a northward invasion.
North Korea fired between 10 and 100 rounds according to different sources.
Pyongyang's move comes shortly after Seoul ended large-scale five-day Navy drills near the inter-Korean border in a show of force against its communist neighbor blamed for sinking a South Korean warship in March. RIA Novosti
