Ukraine has called upon the International Tribunal for the Law of the Sea to order the immediate release of 24 Ukrainian sailors and three navy ships that were seized by Russia in the Kerch Strait in November 2018, off the coast of Russia-occupied Crimea.
Russia claims the Ukrainian Navy ships illegally entered Russian territorial waters near Crimea, which Russia seized and forcibly annexed from Ukraine in 2014, Radio Free Europe / Radio Liberty's Ukrainian Service said.
At the start of the May 10 hearing at the Hamburg-based court, Ukraine's Deputy Foreign Minister for European Integration Olena Zerkal said the tribunal should use "interim measures that require Russia to immediately release the Ukrainian naval ships and their crew members and return them to Ukraine."
The first day of the trial on May 10 was devoted to Ukraine's arguments. The judges are expected to rule on the case before the end of May.
Russia is not taking part in the trial. The Kremlin has said the UN court does not have jurisdiction over its military activities.
Ukraine has been seeking the release of the sailors and ships since Russian forces attacked and seized them in the Kerch Strait, which links the Black Sea with the Sea of Azov.
In January, the European Union reiterated its call for Moscow to release all detained Ukrainian citizens, including the sailors, that Russia is holding.
Brussels maintains that the sailors were "illegally detained" by Russia within the territorial waters of Ukraine's Russian-occupied Crimea Peninsula.
Relations between Russia and Ukraine have been tense since Moscow annexed Crimea in March 2014 and began providing military, political, and economic support to illegal armed formations waging a war against Ukraine in the country's east.