According to Turkish media, seven active generals, including Generals Nusret Tasdeler, the head of the army’s educational command and Ismail Hakki Pekin, the intelligence chief of the general staff, are among the 14 suspects.
Retired General Hasan Igsiz, the former head of the First Army, is also reported to be among the suspects.
They are accused of setting up websites to publish anti-government propaganda with the eventual aim of bringing the government down.
There were no immediate reports of officers being detained.
The investigation into the propaganda websites was launched in 2010.