Note that, Russian Navy ship, the Tsesar Kunikov, passed through the Bosporus with soldiers armed with air-defense systems on the deck on Sunday. The systems are believed to be “Strela” or “Igla” man-portable air-defense systems. Foreign Minister Mevlut Cavusoglu called the incident a provocation after the footage surfaced in the Turkish media. Minister of Transport, Maritime and Communication Bineli Yildirim, meanwhile, has said this incident is a violation of the Montreux Convention, a 1936 multinational treaty that defines the legal regime in the Turkish straits. According to the Convention, in case of any threat from another country, Turkey may obstruct that country’s warships.
Following the incident, three NATO warships cast anchor in the strait.