Russia has announced it is suspending its involvement in the internationally-brokered deal that allows Ukraine to export grain from its Black Sea ports.
It comes after Russia accused Ukraine of a “massive” drone attack on the Black Sea Fleet in Sevastopol, Crimea.
Ukraine has not admitted the attack and President Volodymyr Zelensky called the Russian move “rather predictable”.
Without providing evidence, Russia also accused British troops of being involved in Saturday’s attack.
It also accused the UK of blowing up gas pipelines last month.
In its response, the UK Ministry of Defence (MoD) said Russia was “peddling false claims of an epic scale”.
Russia’s defence ministry says drones used in Saturday’s attack targeted ships involved in the grain deal. It said one vessel had received minor damage.
Hours later, a statement by the foreign ministry in Moscow said: “The Russian side cannot guarantee the safety of civilian dry cargo ships participating in the ‘Black Sea Initiative’, and suspends its implementation from today for an indefinite period.”
It said the move was “in connection with the actions of the Ukrainian armed forces, which were led by British specialists” and that these actions “were directed… against Russian ships that ensured the functioning of the said humanitarian corridor”.