Russian sea mines warning comes as Ukrainian navy says 12 cargo vessels preparing to travel to Ukraine Black Sea ports.

The warning comes as Ukraine’s navy said that 12 cargo vessels were ready to enter a fledgling Black Sea shipping corridor on their way to Ukrainian ports, a significant increase in maritime traffic to Ukraine in defiance of a de facto Russian blockade of the country’s sea ports.

The UK’s foreign office said in a statement on Wednesday that intelligence assessments indicated that Russia was considering the use of sea mines to deter civilian ships travelling through a “humanitarian corridor” established by Ukraine to facilitate grain exports from the Black Sea ports.

“Russia almost certainly wants to avoid openly sinking civilian ships, instead falsely laying blame on Ukraine for any attacks against civilian vessels in the Black Sea,” the Foreign Office said in a statement.

“By releasing our assessment of this intelligence, the UK seeks to expose Russia’s tactics to deter any such incident from occurring,” it added.

The UK’s Foreign Secretary James Cleverly was quoted as saying that “the world is watching” what unfolds in the Black Sea and “Russia’s cynical attempts to lay blame on Ukraine for their attacks”.

Russia pulled out of a deal in July that had allowed Ukraine to safely ship food products out through the Black Sea, which is traditionally its main export corridor.

Moscow shortly after announced that ships in the vicinity of Ukraine’s Black Sea ports would be considered potential supporters of Kyiv’s war efforts and “parties to the Ukrainian conflict”.

Russia has also stepped up aerial attacks on Ukraine’s ports with drones and missile raids that have so far damaged 130 infrastructure facilities and destroyed nearly 300,000 tonnes of grain – enough to feed more than one million people for a year, the UK said.

Ukraine responded by setting up a temporary “humanitarian corridor” on the Black Sea for cargo vessels willing to risk travelling to its ports, and several ships have since used the route.

On Wednesday, Ukrainian Navy spokesperson Dmytro Pletenchuk said that more than 20 ships were preparing to exit and enter Ukraine’s sea ports.

“In total to enter the new corridor we have 12, and 10 to leave. That is as of now,” Pletenchuk said, though he did not say when the vessels were expected to sail.

Ukrainian defence forces are doing everything to ensure the safety of civilian ships in Ukraine’s territorial waters, he said, and the vessels were also proceeding into the waters of Romania, Bulgaria and Turkey, all of which are NATO member countries.

At least seven new ships have entered Ukrainian waters in the past several days, and they are due to ship abroad at least 127,000 tonnes of Ukrainian-origin grain, local Ukrainian officials and lawmakers said.

Kyiv has also increased exports from its ports on the Danube river to Romania and then onwards by road to international markets.

Since the end of the grain deal, Ukraine’s attacks on Russia’s Black Sea fleet in the Moscow-annexed Crimean peninsula and the port city of Sevastopol have increased.

Attacks by Kyiv on Sevastopol were likely responsible for Moscow recently transferring the Black Sea fleet vessel from Crimea to the Russian port of Novorossiysk in the Krasnodar Krai region of Russia, Washington, DC-based think tank, the Institute for the Study of War (ISW), said in its latest Ukraine war monitoring report.

Satellite imagery between October 1 and 3 showed that Russia had transferred 10 vessels to Novorossiysk from Sevastopol, the ISW said.

NEW: The Russian military recently transferred several Black Sea Fleet (BSF) vessels from the port in occupied #Sevastopol, Crimea to the port in Novorossiysk, Krasnodar Krai, likely to protect them from cont’d UKR strikes on RU assets in occupied #Crimea. https://t.co/2vyVd0sqDr pic.twitter.com/osVN1oefI2

— ISW (@TheStudyofWar) October 5, 2023

Last month, the UK accused Russia of attempting to attack a civilian cargo ship at a port in the Black Sea on August 24 in a missile attack it said was successfully thwarted by Ukrainian air defence systems.

The UK also said that it was working with Kyiv and other partners to improve the safety of Ukrainian shipping, and was using its intelligence, surveillance and reconnaissance capabilities to monitor Russian activity in the Black Sea.