South Korea's military has investigated about 70 officers found to have had memberships at a now-closed pro-North Korea online community site.
The Defense Ministry said Monday that seven to eight of the officers committed "problematic" behavior by posting messages on the site and will face further investigation.
It says the rest simply obtained membership out of curiosity.
Local media reports say South Korean authorities have blocked the site from being accessed because it contained articles praising North Korea's political system and leader Kim Jong Il's moves to transfer power to a son.
The Koreas are still technically at war because the Korean War in the 1950s ended with an armistice, not a peace treaty.