Russian drones attacked three foreign-flagged merchant vessels late Thursday and overnight in the Black Sea, Ukraine's Deputy Prime Minister Oleksiy Kuleba said on Friday.
The strikes caused fires on the vessels, but crews extinguished them, Kuleba said on Telegram.
Ukraine's seaports authority said the ships sailed under the flags of Vanuatu, Comoros, and Panama.
The Ukrainian navy earlier reported a strike on the Ant, a Turkey-owned cargo ship under Vanuatu flag, heading to Turkey from one of Odesa ports.
The attack caused a fire and evacuation of two injured crew members. The vessel was laden with cargo at the time.
Russia has repeatedly targeted maritime export routes since its invasion over four years ago.
