An Estonian-owned cargo ship sank on Thursday off Ukraine's major Black Sea port of Odesa, hours after a Bangladeshi vessel was hit by a missile or bomb at another port, underlining the growing peril to merchant shipping following Russia's invasion of Ukraine.
Many shipping firms have suspended sailings to affected Black Sea ports and other terminals in Ukraine, with insurance premiums for voyages soaring in recent days. At least three commercial ships have been hit by projectiles since February 24.
Six crew members from the Marshall Islands-flagged and Estonian-owned Helt cargo ship were picked off by the Ukrainian Rescue Services, the Ukraine Maritime Administrator said.
Two crew members were in a life raft at sea while four others were previously unaccounted for, Igor Ilves, managing director of Tallinn-based manager Vista Shipping Agency, told Reuters.
"The vessel has finally sunk," he said. "Two of the crew are in a raft on the water and four others are missing. I don’t know where they are at the moment."
Ilves said the vessel might have struck a mine.
"It’s a big problem - nobody can help them. The Ukrainians cannot go to sea because it is under Russian control."
Ilves said the crew comprised four Ukrainian nationals, one Russian and one Belarusian.
NATO's Shipping Center warned on Wednesday that there was "a high risk of collateral damage on civilian shipping in the northwestern part of the Black Sea," which included mines.
"There are several open-source reports of civilian ships being hit directly or indirectly as a result of the acts of war in the northwestern Black Sea within Ukrainian territorial waters and adjacent international waters," NATO said.
"Civilian shipping is encouraged to exercise caution and be on high alert in the area."
This comes as Ukraine's Armed Forces accused the Russian Black Sea Fleet of using civilian vessels as human shields.