South Korea's Joint Chiefs of Staff office has reported that the Republic of Korea Navy fired warning shots Sunday at a pair of North Korean patrol boats that had crossed the Northern Limit Line (NLL) into South Korean waters.
Tensions have escalated since the mysterious sinking on March 26 of a South Korean warship, 'Cheonan', which resulted in the death of 46 sailors. The incident is believed to be the result of a North Korean torpedo attack.
Korea Institute for Defense Analyses analyst Baek Seung-Joo told AFP the incursion was an attempt to establish territorial claims by North Korea, which has never recognised the UN-drawn NLL. The area is reportedly an important crab-fishing site.
Investigations continue into the cause of the 'Cheonan' sinking.