In late November, Ukraine’s Berdyansk and Nikopol gunboats and the Yany Kapu tugboat illegally crossed the Russian maritime border as they sailed toward the Kerch Strait, the entrance to the Sea of Azov. The Ukrainian vessels were seized by Russia after failing to respond to legal demands to leave the area. Moscow described the incident as a clear provocation in violation of the United Nations Convention on the Law of the Sea and promised to suppress any attempts to challenge its territorial integrity and sovereignty.
On November 25 border patrol boats belonging to Russia’s FSB security service seized two small Ukrainian armoured artillery vessels and a tug boat and their crews after opening fire at them, wounding several Ukrainian servicemen. Russia argued that they were in Russian waters. However a bilateral treaty between Russia and Ukraine, signed in 2003 and ratified by Russia in 2004, governs the use of the Kerch strait and the Sea of Azov, which in the treaty is considered to be the “internal waters” of both Russia and Ukraine. See recurring disinformation examples about the Azov Sea.