The Kerch Strait incident was an international incident that occurred on 25 November 2018 in the Kerch Strait, during which the Russian Federal Security Service (FSB) coast guard fired upon and captured three Ukrainian Navy vessels after they attempted to transit from the Black Sea into the Sea of Azov through the strait on their way to the port of Mariupol.[9][12] It was the first time that Russian forces had openly engaged Ukrainian forces during the Russo-Ukrainian conflict.