The main opposition Liberty Korea Party(LKP) has demanded the resignation of the defense minister over alleged security breach after a North Korean boat was found to have drifted deep into South Korean waters last weekend. 

Speaking at a general meeting of the main conservative party on Wednesday, LKP Floor Leader Na Kyung-won said fishers not the military defend the nation, apparently in reference to the fact that the North Korean boat was first reported by a South Korean fishing boat off the coast of Samcheok, Gangwon Province. 

Na said Defense Minister Jeong Kyeong-doo should resign instead of finding someone else to be held responsible, while calling for an inquiry into the case by the National Assembly National Defense Committee. 

She demanded that inter-Korean military agreements also be scrapped immediately. 

The North Korean fishing boat carrying four North Koreans managed to drift some 130 kilometers south of the inter-Korean maritime border before it was detected. During a military commanders' meeting early on Wednesday, Jeong stressed the need to identify and fix flaws in current detection practices.