REUTERS Ukrainian Prime Minister Volodymyr Groysman says vessels flying the Ukrainian flags in the Sea of Azov account for a mere 10%, thus Russia has been blocking mainly ships of other countries in violation of all laws. Read alsoEU ready to strengthen support for Ukraine after Russia&#39;s blocking of Azov shipping "A mere 10% of the ships are flying the Ukrainian flags. Vessels flying the flags of the EU member states are among the remaining 90%," he said at a press conference on December 17 after the 5th meeting of the Ukraine-EU Association Council. Therefore, Russia is blocking vessels of other countries, violating all norms and causing damage to their economies. "Tit-for-tat measures to be taken by our partners against Russian-flagged vessels would be a fair response," the head of government stressed. UNIAN memo. On November 25, Russia blocked the passage to the Kerch Strait for the Ukrainian tugboat "Yany Kapu" and two armored naval boats "Berdyansk" and "Nikopol," which were on a scheduled re-deployment from the Black Sea port of Odesa to the Azov Sea port of Mariupol. The Ukraine Navy Command noted that the Russian side had been informed of the plans to re-deploy the vessels in advance in accordance with international standards to ensure the safety of navigation. The Russian coast guard ship "Don" rammed the Ukrainian tugboat, damaging the Ukrainian vessel. As the Ukrainian boats were heading back in the Odesa direction after being rejected passage via the Kerch Strait, Russian coast guards opened aimed fire on them. All 24 crew members on board were captured and later remanded in custody for two months, being charged with "illegal border crossing" (the sailors are facing up to six years in prison). Three crewmen were wounded in the attack. Russian-controlled "courts" in occupied Crimea ruled that all 24 detainees should be remanded in custody, after which they were transferred to the Moscow-based Lefortovo and Matrosskaya Tishina detention centers.