NATO has reacted to the capture by Russia's fleet of the Ukrainian navy's boats near the Kerch Strait.

"NATO spokesperson: 'NATO fully supports Ukraine's sovereignty and its territorial integrity, including its navigational rights in its territorial waters. We call on Russia to ensure unhindered access to Ukrainian ports in the Sea of Azov, in accordance with international law,'" Brussels reporter for Radio Free Europe/Radio Liberty Rikard Jozwiak tweeted on Sunday evening.

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On Sunday morning, Russia blocked the Kerch Strait passage between the Black Sea and the Sea of Azov. Two small-sized armored artillery boats, the 'Berdiansk' and the 'Nikopol,' together with the 'Yany Kapu' tugboat – all belonging to Ukraine's Navy – were unable to cross the Kerch Strait. They were moving from the port of Odesa in the Black Sea to the port of Mariupol in the Sea of Azov. Later all the three boats with 23 people on board were captured by Russia's special forces on Sunday evening. Six Ukrainian navy men were reportedly wounded; two of them were in serious condition.