Three Ukrainian ships are to be returned almost a year after the Russian navy seized the vessels in the Kerch Strait.
Tug boats were seen towing the vessels through the strait, which separates Crimea from the Russian mainland, a photographer working for the Reuters news agency reported.
Separately, Russia's security service FSB said that the three vessels would be handed over to Ukraine on Monday.
Russia's military had captured a tugboat and two small artillery vessels last November after the Ukrainian crews tried to gain access to the Sea of Azov.