According to the prosecutor’s office, it's because they're accused of having links to the network of US-based cleric Fethullah Gulen.
Ankara says it was him who orchestrated a 2016 attempted coup.
Those who are facing jailtime include three colonels, eight majors and 10 lieutenants.

Bahrain, Kuwait, Jordan face renewed Iranian attacks after US hits Iran's south
Lebanese army enters southern town after Israeli withdrawal, in first test of US-brokered deal
Kuwait lodges formal protest with Iran over tanker attack; ministry says power station fires contained
Russian attack kills three in Ukraine's Zaporizhzhia, officials say
French parliament backs social media ban for children under 15
