South Korea's military has deployed more rocket artillery to two islands near the Yellow Sea border to guard against a possible attack by North Korea, a government source said Monday, amid high tensions following the North's deadly shelling of one of the islands.

An unspecified number of the homegrown 130-millimeter "Kuryong" multiple rocket launchers were recently installed on Baengnyeong and Yeonpyeong islands, the source said on the condition of anonymity.

"The deployment of the Kuryong is aimed at bolstering capabilities of a retaliatory attack in case of emergency," the source said.

The South's military has pledged tougher retaliation amid criticism over its perceived slow and weak responses after the North's bombardment of Yeonpyeong last November, which killed two marines and two civilians.

Marine units on the islands will soon have an operational command for the additional multiple rocket launchers, the source said.

With 36 launch tubes and a shooting range of 23-36km, a Kuryong is believed to be superior to the North's 120-mm rocket artillery. 

(Yonhap News)