Russia's Foreign Intelligence Service warned that Britain is planning to carry out a "provocation" involving an attack on "a civilian foreign ship in a European port," TASS reported.
"Members of the group have already arrived in Britain for sabotage training. Once the terrorists are "exposed", they plan to claim they acted on "Moscow's orders," the agency said.
The SVR also said that the Ukrainian fighters would be carrying Chinese-made underwater equipment that would later be used as evidence of Beijing's support for Russia's war in Ukraine.
The agency said that "London's rapid slide to the periphery of world history" had prompted British intelligence services to try to pit "the world's biggest players against each other," while noting that such attempts would fail.