About 140 ships have been trapped off the coast of Ukraine, putting more than a thousand seafarers in harm’s way.

Since Russian troops first began the invasion last week, a dozen oil-product tankers, a sunflower oil carrier, and 45 bulkers used to transport grains, ore and coal have gotten stuck, according to ship-tracking data compiled by Bloomberg. There are also 54 cargo carriers and a container vessel that sailed into Odesa just before the harbor closed.

At least five merchant ships have been blown up in the region since the attack started, highlighting the risk that the crews are facing.

Last known positions of commercial vessels trapped in Ukraine after Feb. 24. (yellow dots). Excludes Crimea
Last known positions of commercial vessels trapped in Ukraine after Feb. 24. (yellow dots). Excludes Crimea

Vessels can’t leave Ukrainian waters because there are no harbor pilots to guide them out, according to owners and ship managers. More importantly, navigation in parts of the northwest Black Sea is restricted due to the threat posed by underwater mines, according to an alert posted on the Spanish Navy’s website.

At least some of the stranded vessels have cargo on board, according to people with knowledge of the vessels in the area.

Panama-flagged cargo ship Helt sank after being hit below the waterline, prompting rescue operations to bring ashore six crew, said Ukraine’s Administration of Sea Ports. Meanwhile, an engineer on Bangladesh Shipping Corp.’s vessel Banglar Samriddhi died when a missile hit the ship.

Intense fighting and shelling have continued in cities across the key agriculture exporter. That’s led to a surge in commodities prices of everything from food to energy, while shippers scramble to divert thousands of containers of goods to other ports. Oil prices are also soaring because some tanker companies are unwilling to let their ships lift Russian barrels for the time being.

A typical ocean-going merchant ship will have 20 or more crew members on board, implying well over 1,000 seafarers would be stuck.

“All ports are blocked,” said Henrik Jensen, managing director of Danica Crewing Specialists, which provides services to two ships stuck in Ukraine with 40 crew on board, all of whom are uninjured. “This is a terrible situation.