Russian defence ministry TV channel Zvezda has published footage showing a Russian border guard ship converging on and escorting Ukrainian Navy ships as they approach the Kerch Strait.
Earlier, Sputnik reported that at around 7 am Moscow time, three Ukrainian Navy vessels illegally crossed the maritime border with Russia and proceeded to move through the Kerch Strait from the Black Sea. Two more Ukrainian vessels were later reported to be heading to the area from the Sea of Azov.
The situation in the Sea of Azov and around the Kerch Strait was aggravated in March, after Ukraine detained a fishing trawler with ten Russian nationals onboard, and then again in August, when a Russian sailor was arrested in the Ukrainian port of Kherson. Moscow has described Ukraine's actions as "maritime terrorism," and strengthened its maritime border in the Sea of Azov.