South Korean President Lee Myung-bak suggested Monday militarily fortifying five front-line islands following the Democratic People's Republic of Korea (DPRK)'s shelling of one of the western islands, Lee's office said.

Lee instructed the Cabinet to "gradually push for militarily fortifying" the five border islands deemed vulnerable to further provocations by the DPRK, his office Cheong Wa Dae said.

The remark comes as concerns rise that the islands might come under further attack amid heightened tension following the DPRK's artillery bombardment of Yeongpyeong Island on Nov. 23, which killed two marines and two civilians.

The government recently announced it will spend 30 billion won (26 million U.S. dollars) to help displaced residents get back on their feet and pass a special law designed to support living conditions in the five islands.