SEOUL, May 21 (UPI) —
Three North Korean patrol boats crossed into South Korean territory Tuesday, prompting a South Korean naval vessel to fire 10 warning shots.
The incident occurred around 4 p.m. local time by Northern Limit Line border at the Yellow Sea. The North Korean ships returned after the warning shots were fired, an official with the South Korean defense ministry said.
The NLL boundary was established by the United Nations after the Korea War but is not recognized by the North.