The South Korean Defense Ministry said troops along the border discovered balloons containing thousands of leaflets this week. The leaflets issued statements blasting alleged attempts to destroy a statue of late North Korea leader Kim Il Sung.
"It seems that North Korea (sent them) to claim legitimacy of its regime," ministry spokesman Kim Min-seok was quoted by the Yonhap news agency as saying. "Analysis is currently under way to figure out (their) intentions."
In 2000, both sides agreed to halt psychological operations near the border and, in 2004, both governments pulled down propaganda along the shared border.
Tensions in the Korean Peninsula have intensified since Kim Jong Un took control over the country after the December death of his father, Kim Jong Il.
A top North Korea military adviser was sacked this month. Kim was recently named supreme commander of the country's military.