South Korea's military is planning to install underwater sensors near frontier islands in the Yellow Sea to guard against attacks by North Korea's submarines.
"We plan to install a number of underwater sensors to beef up defence capability in strategically important north-western islands like Baengnyeong and Yeonpyeong following the sinking of the Cheonan warship," an unidentified senior military official said.
The sensors will be monitored from a control centre located on Baengnyeong island, the closest one to the border with North Korea, according to Agence France Presse.
The South Korean Defence Ministry declined to disclose any further information.
South Korea has been staging a series of military exercises including a joint naval drill with the US in a move to display its strength against North Korea.