Erdogan accuses former admirals of "political coup"

Turkish President Recep Tayyip Erdogan on Monday accused dozens of retired admirals of eyeing a "political coup" by attacking his plans for a canal linking the Black Sea to the Mediterranean.

Police have detained ten of the former navy commanders and ordered four others to turn themselves in after they published an open letter critical of the proposed Canal Istanbul over the weekend.

Turkey's post-Ottoman history is littered with putsches by a military that views itself as the last guarantor of secularism in the mostly Muslim country.

Erdogan's fury was directed at a letter published by 104 former admirals over the weekend urging him to abide by the terms of the 1936 Montreux Convention.

The treaty is aimed at demilitarising the Black Sea by setting strict rules on warships' passage through the Bosphorus and Dardanelles straits.

But Erdogan's plan to build a new 45-kilometre (28-mile) shipping lane running to the west of the Bosphorus leaves open the question of whether the old treaty will apply to the proposed canal.

The retired admirals said the 1936 treaty "best protects Turkish interests".

Erdogan told them on Monday that "the duty of retired admirals – 104 of whom come together – is not to publish declarations that hint at a political coup".

"In a country whose past is filled with coups, (another) attempt by a group of retired admirals can never be accepted," he said after chairing a meeting with his top aides.

The Ankara chief prosecutor has accused the former commanders of "using force and violence to get rid of the constitutional order", NTV broadcaster reported.

The wording is similar to what prosecutors have used against other Erdogan critics jailed in a crackdown that followed a failed putsch in 2016. (AFP)