A Russian Navy spy ship conducting signals intelligence (SIGINT) operations against the United States in Syria sank in the Black Sea after colliding with a freighter off Turkey's northern coast.

The "naval reconnaissance" ship Liman sank some 25 miles northwest of the Bosphorus Strait. The collision between the Togo-flagged freighter Youzarsif H. loaded with sheep and the Russian spy ship occurred in foggy conditions with poor visibility.

Liman recently returned from a three-month deployment off the coast of Syria in February where she launched SIGINT operations against the U.S. and its coalition partners fighting to oust the regime of Syrian president Bashar al-Assad, who is being backed by Russia with air strikes and cruise missile strikes from Russian Navy warships in the Black Sea.

The Russian foreign ministry said Turkish ships rescued all 78 of the Russian Navy crewmen aboard the Liman. None of the Russians was injured but the spy ship and its secret spying equipment was a total loss.

Turkey said Prime Minister Binali Yildirim had called his Russian counterpart, Dmitry Medvedev, to express his "sadness" over the collision.

"On April 27 at 11:53 Moscow time, in the southwestern part of the Black Sea, 40 kilometers northwest of the Bosphorus Strait, the research vessel of the Black Sea Fleet, the Liman, as a result of a collision with the Ashot-7 vessel ... received a starboard hole below the waterline. No one was injured among the crew. The crew ... are fighting for the survivability of the vessel," said a statement in Russian media.

"All crew members of the research ship of the Black Sea Fleet are alive and well and are currently preparing for evacuation from the Turkish rescue ship to a Russian ship," said the Defense Ministry.

The Liman is so secret not much is publicly known about this spy ship.