Ankara: Turkey has detained 10 retired admirals over their public criticism of Recep Tayyip Erdoğan’s “crazy” Istanbul canal project.

The project aimed to will create a new waterway from The Black Sea to the Mediterranean in addition to the existing Bosphorus strait.

The arrest warrants issued came a day after a group of 104 former senior navy officials signed an open letter warning that the proposed canal could harm Turkish security by overturning an 85-year-old international accord

Local Turkish media say all the former officers have been detained in connection with an ongoing investigation into an open letter against the government presented by Turkey's chief prosecutor in the capital, Ankara.

“Montreux provided Turkey with the possibility to maintain its neutrality during the second world war. We are of the opinion that there is a need to avoid any statements and actions that could cause the Montreux convention, an important treaty in terms of Turkey’s survival, to be brought up for discussion,” the statement from the retired navy personnel said.

Turkey's chief prosecutor has ordered four more suspects to report the matter to Ankara police within three days, although they have not been detained because of their elderly age.

The detained former senior officers have been accused of using force and violence to circumvent the constitutional order.

The custody came following the discovery of a letter signed by 104 retired admirals, which has been strongly condemned by the Presidential Office.

“A group of retired soldiers are putting themselves into a laughable and miserable position with their statement that echoes military coup times,” the presidential spokesperson İbrahim Kalın said on Twitter.

“The [group] should know that our esteemed nation and its representatives will never allow this mentality,” he added.

Erdoğan’s top media advisor, Fahrettin Altun, said: “Not only those who signed but also those who encourage them will give an account before justice.”