From the New York Times:

The top commanders of Turkey’s military resigned suddenly and en masse on Friday, the semi-official Anatolian News Agency reported, in a dramatic signal of deepening tensions between the armed forces and the country’s Islamic-rooted government.
The military chief of staff, Isik Kosaner, sent a letter of resignation to the prime minister’s office on Friday, the agency said, without elaborating on his reason. The commanders of the country’s navy, army and air force followed shortly after with their own letters, the news agency said.
Earlier on Friday, Mr. Kosaner met with the prime minister, Recep Tayyip Erdogan, and President Abdullah Gul, according to local media reports. Mr. Kosaner as well as the army commander, Gen. Erdal Ceylanoglu; the navy chief, Adm. Esref Ugur Yigit; and the commander of the air force, Gen. Hasan Aksay, stepped down following that meeting, according to an account in the daily Hurriyet.
It was not immediately clear why the country’s top military leaders would resign all at once. The Associated Press reported that the move came only hours after 22 people, including several generals and officers, were charged in a campaign on the Internet to undermine the civilian government.

The rest here.