South Korean President Lee Myung-Bak today called for national unity in the face of North Korean attacks, saying the communist state would exploit divisions in the country to strike again. In a fortnightly radio address, Lee told South Koreans not to fear war even though Seoul's hope is for peace. The South has staged a series of military exercises, including one with the United States, since the North shelled an island near the disputed Yellow Sea border last month and killed four people, including two civilians. From today, it will stage naval daring drills at twenty three venues till 31st of December. Meanwhile, the North's ruling communist party newspaper branded the exercises a dangerous collusion between Seoul and Washington that would lead to destruction.