Ukraine accused Russia on Sunday of opening fire on its ships near Crimea, hitting at least two navy vessels and leaving several crew members wounded. Ukrainian President Petro Poroshenko has called an emergency meeting of top military officials over the incident, which occurred while three Ukrainian ships were sailing from Odessa, which is on the Black Sea, to Mariupol, which is on the Sea of Azov, officials in Kiev said. Ukraine’s Defense Ministry said in a statement that three navy ships—two gunboats and a tugboat—were fired at and seized by Russian forces. Russia’s Federal Security Service confirmed that its border agents had “used weapons” against the three ships before seizing them but claimed that the Ukrainian ships had illegally crossed into its waters. Ukrainian officials said six service members were injured in the incident, while Russia put the number at three. The Sea of Azov is situated east of Crimea, which was annexed by Russia in 2014. It’s also south of the Ukrainian areas that have been occupied by pro-Russian separatists. United Nations Ambassador Nikki Haley tweeted Sunday that the Security Council will hold an emergency meeting Monday to discuss the matter.