The Ukrainian navy said on social media six Ukrainian sailors were wounded in the subsequent seizure of its ships, which appear to have been rammed and boarded, and that the Russian attack on them had occurred after they had retreated and headed back toward Odessa, the Black Sea port from where they had begun their journey. With relations still raw after Russia's 2014 annexation of Crimea and its backing for a pro-Moscow insurgency in eastern Ukraine, the incident risks pushing the two countries towards a wider conflict and is likely to renew Western calls for more sanctions on Moscow. Russia's Federal Security Service (FSB), which oversees the country's border guard service, said it was forced to open fire on the ships on Sunday after they illegally entered Russian territorial waters. Poroshenko said at a meeting of Ukraine's national security council Monday that "we demand that (the ships and crews) are urgently turned over to the Ukrainian side" and called for a "de-escalation" of the crisis around Crimea. The European Union and NATO called for restraint from both sides and for Moscow to restore access to the strait, which Ukraine uses to move ships to and from ports on either side of the peninsula. Russia's FSB security service said early on Monday its border patrol boats had seized two small Ukrainian armoured artillery vessels and a tug boat after opening fire on them and wounding several sailors, the most serious clash between Moscow and Kiev in years. It had previously blocked the Kerch Strait near Russia-annexed Crimea to stop the ships from passing from the Black Sea into the Sea of Azov, saying the small flotilla had not notified it of its plans in advance and ignored warnings to stop while manoeuvring dangerously. The United Nations gave overwhelming support to a 2014 resolution underscoring Ukraine's territorial integrity following Russia's seizure of Crimea and with Russia-backed separatists fighting for control of swaths of eastern Ukraine in 2014. Russia has bolstered naval forces into the area over the past year -- with an overmatched Ukraine trying to do the same -- and routinely detained Ukrainian vessels in waters that Kyiv still regards as its own or at least shared, according to a bilateral agreement from 2003. The Ukrainian Foreign Ministry said earlier that Russia’s actions violated the U.N. Charter and international law, and pledged to “promptly inform our partners about Russia’s aggressive actions.”

“Such actions pose a threat to the security of all states in the Black Sea region,” the statement said, “and therefore require a clear response from the international community.”

Ukrainian President Petro Poroshenko, after a meeting with his National Security Council, said in a statement he would ask parliament Monday to take up the issue of whether to implement martial law over the incident.
Russia stops three Ukrainian Navy vessels from passing under the Kerch Strait Bridge by blocking it with a cargo ship. Russia claims they violated her territorial waters and ignored warnings. The navy vessels and their crews are seized after shots were fired. Russia says three Ukrainians were wounded. According to Ukraine, six of their sailors are wounded. Ukraine denies their ships did anything wrong.