South Korean President Lee Myung-bak is calling for national solidarity against military aggression by the DPRK. He says Pyongyang is looking for division in the South as an opportunity to strike.

President Lee says divided public opinion following the sinking of a South Korean navy ship in March prompted Pyongyang to bombard Yeonpyong Island.

Seoul blames the DPRK for sinking the Cheonan and the death of 46 sailors. Lee has toughened his language against the North.

Analysts say the frequency of DPRK attacks have pushed him against a political wall, and he has little choice but to order a harsh retaliation which could spark a wider military conflict.