A Russian destroyer has used small arms fire to ward off a Turkish fishing ship and prevent a collision in the Aegean Sea, the Defence Ministry said.
The guided missile destroyer Smetlivy was unable to establish radio contact with the approaching Turkish boat, which also failed to respond to visual signals and flares, the ministry said in a statement.
When the Koroglu Balikcilik was about 660 yards away, warning shots were fired from the destroyer and the Turkish vessel quickly changed course, passing within 600 yards.
The incident occurred in the northern part of the Aegean, about 13 miles from the Greek island of Lemnos, the ministry said.
Tensions between Moscow and Ankara have been heightened since a Turkey downed a Russian warplane along the Syrian border last month, and this could further strain relations.
The Defence Ministry summoned the Turkish defence attache in Moscow over what it described as the "provocative actions" of the Turkish ship.
Russian deputy defence minister Anatoly Antonov informed Turkish Rear Admiral Ahmet Gunes of "the possible harmful consequences of the reckless actions of Ankara in regard to the Russian military contingent fighting international terrorism in Syria", the ministry said in a statement.
Turkish foreign minister Mevlut Cavusoglu said Turkey would get the fishing ship's side of the story before making an announcement, but added that Turkey does not want an escalation of tensions.
"We don't want tensions. We want to overcome tensions through dialogue," Mr Cavusoglu said.