Turkey blocked 27 Russian ships from sailing toward the Mediterranean and Black seas this week allegedly for failing to meet the necessary sailing criteria amid escalating tension between the two countries. The move followed a similar decision by Russia, which is currently holding eight Turkish vessels in its ports after Turkey shot down a Russian warplane, the Daily Sabah in Istanbul reported Wednesday.

Moscow suspended its links with Ankara and began implementing nonreciprocal trade ties and custom practices last month after the Russian Su-24 fighter jet was downed by Turkey for allegedly violating its airspace near the Syrian border. Russian President Vladimir Putin denied any violation and warned the Nov. 24 incident will have “significant consequences” for Moscow-Ankara relations. The Russian military has been conducting airstrikes in Syria apart from the U.S.-led coalition targeting the Islamic State group.

Putin said the downing of its plane was "beyond the normal framework of fighting against terrorism. Of course our military is doing heroic work against terrorism. ... But the loss today is a stab in the back, carried out by the accomplices of terrorists. I can’t describe it in any other way,” the British newspaper the Guardian reported. "Neither our pilots nor our jet threatened the territory of Turkey. This is obvious.”



Ankara said Turkey does not need to apologize for the incident, stressing its right to protect its skies. “The protection of our land borders, our airspace, is not only a right, it is a duty. We apologize for committing mistakes, not for doing our duty,” Turkish Prime Minister Ahmet Davutoğlu said Dec. 1, Middle East Monitor reported.

Moscow has since detained Turkish travelers, stopped Turkish vehicles from crossing into Russia and now denied Turkish trade ships from entering Russian ports. Russian Prime Minister Dmitry Medvedev Wednesday called for expanded sanctions against Turkey, banning joint projects in the hospitality industry, woodworking and pilot training. The new measures also would bar Turkish citizens from participating in state purchases, the Russian daily Kommersant reported.

In response, Turkey has tightened its inspections of Russian vessels coming into Turkish ports. Turkish maritime authorities had detained 27 Russian ships as of Tuesday due to missing documents or transactions in line with the Mediterranean and Black Sea memorandums. Russia apparently agreed to meet with Turkey to resolve the stalemate although no date has been set to discuss the issue, unnamed sources told the Turkish daily Habertürk.