Russia said on Thursday it had detained a Russian security guard working at Britain’s embassy in Moscow, alleging he was hired by Ukraine for a false flag attack on the UK ambassador.The FSB security service said the individual had been recruited by a Ukrainian blogger working with that country’s SBU security agency to track events and people at the British embassy and take note of their security system.For all the latest headlines, follow our Google News channel online or via the app.Ukraine then “planned to use this obtained information to prepare and carry out sabotage and terrorist attacks against the head of the British diplomatic mission and other diplomats, and then accuse the Russian side,” the FSB said in a statement.Kyiv and London have not responded to the allegations.Britain is one of Ukraine’s closest allies and backers, providing billions of dollars in military and financial aid.Relations between Russia and Britain were frosty long before Moscow launched its full-scale Ukraine offensive in 2022 -- marred by several spy and assassination scandals.They include the 2006 poisoning of ex-Russian spy Alexander Litvinenko in London and the 2018 attempted poisoning of double agent Sergei Skripal in Salisbury, which killed a member of the British public.On Wednesday, British prosecutors said they had charged a 31-year-old British man for allegedly making contact with a representative of Russia’s GRU military intelligence agency.Read more: Zelenskyy’s plane ‘almost hit’ by drone on Tuesday, Norway PM says