Russia fired on two foreign ships near the Black Sea port of Pivdennyi on Friday, Ukraine's infrastructure ministry said on its Facebook page.
Russia fired on "Namura Queen" under Panama's flag and "Millennial Spirit" under Moldova's flag, the ministry said.
The crew had been evacuated and taken to the Chernomorsk port by Ukrainian rescue service, it added.
Ukraine has said it closed all its seaports due to war with Russia.
(Reporting by Pavel Polityuk and Anna Pruchnicka; Editing by Andrew Heavens)