The Russian ship "And Quiet Flows the Don" of the Coast Guard of the Border Service of the Federal Security Service of Russia (FSB) was spotted near Mariupol on the 28th of March, 2016, as reported by Krym.Realii.
The State Border Guard Service of Ukraine reported on March 30th that "The target has been identified as an unarmed patrol vessel of the Russian coast guard. The ships of the Sea Guard of the State Border Guard Service of Ukraine went to escort and monitor 'And Quiet Flows the Don' at around 6:00 PM. When interrogated, the captain stated that the ship regulates the catching of the biological resources in this area.”
The speaker of the Presidential Administration of Ukraine on the War in the Donbas, Andriy Lysenko, stated that the vessel did not violate international law in the waters of the Sea of Azov.
"Under the international agreements between Ukraine and Russia, signed and valid until today, the Sea of Azov is recognized as the internal waters of both Russia and Ukraine. That is, we can use the sea, we might come to their shores and they can come to our shores, so there are no violations. There is no special obvious danger from this vessel," he assured.
At the moment the ship is still under the surveillance and supervision of Ukraine’s coast guard.