Russia is preparing to reroute grain shipments away from the Sea of Azov following Ukrainian drone attacks on tankers, ferries, tugboats and other vessels.

A Ukrainian drone struck a tanker as it was entering the Azov-Black Sea Canal, Yury Slyusar, governor of Russia's Rostov region, said on Sunday.

Vital maritime corridor closes after 90 vessels – including shadow fleet oil tankers – are attacked in under a week