The chief of the Turkish armed forces has resigned, along with the heads of the army, navy and air force, according to the Anatolia news agency.
The BBC reports that there has been a history of tension between the secularist military and the governing AK party, with the two sides engaged in a war of words for the past two years over allegations that parts of the military had been plotting a coup.
Investigations into those allegations - known as the "Sledgehammer" conspiracy - appear to be the root cause of today's resignations, according to the BBC, with the senior military wanting to go ahead with scheduled annual promotions for some of the officers implicated - and the government refusing.
The ''Sledgehammer'' case arose from a plan presented at an army seminar in Istanbul in 2003.
It reportedly involved plans to bomb mosques and provoke tensions with Greece, in order to spark political chaos and justify a military takeover.
The military says it was only a contingency plan based on scenarios of political unrest.
General Kosaner was appointed overall head of the Turkish armed forces just a year ago.
General Hasan Igsiz was initially proposed, but was blocked because he was implicated in ''Sledgehammer''.
The BBC reports that Turkey's President Abdullah Gul moved quickly to appoint General Necdet Ozel as the new army chief, and says he is widely expected to be swiftly elevated to chief of the general staff in place of General Kosaner.
Tradition dictates that only the head of the army can take over the top job.
