Kyiv announced the maritime corridors for civilian vessels last week after Russia exited an agreement allowing safe sea passage for grain exports and threatened cargo ships in the Black Sea.

"The first vessel is moving along the temporary corridors established for civilian vessels to and from Black Sea ports," Ukraine's Infrastructure Minister Oleksandr Kubrakov said in a statement.

It named the vessel as the Hong Kong-flagged Joseph Schulte, and said it had left the port of Odesa, one of three transit hubs that participated in the now scrapped grain deal.

"Ukraine proposed this route in its appeal to the International Maritime Organisation (IMO)," Kubrakov added in the statement.

"The corridor will be primarily used to evacuate ships that were in the Ukrainian ports of Chornomorsk, Odesa and Pivdenny at the time of the full-scale invasion by the Russian Federation," he added.

Over the weekend, Moscow said it fired warning shots from a Russian warship at a cargo vessel heading towards the Ukrainian port of Izmail.

Attacks have increased on both sides of the Black Sea since Moscow exited the grain deal.

Russia has repeatedly attacked port infrastructure on the Black Sea and the Danube in Ukraine, which has targeted Russian warships in the region.