Islam Times reports from Yonhap news agency: A Defense Ministry statement said the shell fired from North Korea landed near the Yellow sea border on Wednesday.
According to the statement, the Navy responded by firing three shots towards the disputed maritime border with the North, off the western coast of the peninsula.
The ministry said its shots landed near the border, known officially as the Northern Limit Line.
Last November, Seoul and Pyongyang exchanged artillery fire in the Yellow Sea border island of Yeonpyeong. The two blamed each other for the launch of the border fighting.
South Korea said it returned fire after North Korean forces shelled one of its islands, but the North said the South fired first. Two South Korean troops died during the clashes.