The United States says it has "credible information" that Russian forces are creating lists of Ukrainians to be killed or sent to camps in the event of occupation. It is the latest claim about Russia's alleged plans to be publicised by Western powers. The Kremlin has denied the existence of any "kill list". And some Western officials acknowledge the alleged plans are speculative, and may not be put into action. But Russia's FSB Security Service is believed to be involved in preparing the political ground for any occupation if orders are given.The little-known Fifth Service of the FSB is likely to play a key role in the event of a significant escalation in Ukraine. he Fifth Service and its Department of Operational Information runs covert operations in many states neighbouring Russia and has taken the lead in Ukraine. It has established networks of agents within Ukraine and has been preparing to activate them in the event of conflict, Western intelligence sources say. The aim will be to limit resistance and ensure control. If there is an attempt to remove the government in Kyiv, that could involve senior figures working in key institutions and industries being approached and instructed to work with Russia - or else face the consequences, it is claimed. Russia has denied plans to invade, and some Western analysts remain sceptical that Russia has the forces or the intent to mount a full-scale occupation with all the risks that this would entail. The claim about a list of targets to be arrested or even killed came in a letter from the US Ambassador to UN organisations in Geneva, to the UN High Commissioner for Human Rights. The US said "likely" targets are those who oppose Russian actions, including Russian and Belarusian dissidents in exile in Ukraine, journalists and anti-corruption activists, as well as religious and ethnic minorities and LGBTQ+ persons. The letter says the US also has information that Russia plans to use lethal measures to disperse protests if there is an occupation. The letter is the latest salvo in Washington's attempts to expose what it says are Moscow's plans for Ukraine. The US has not presented further details or cited the source of its information. And it is not clear how far any such plans might have progressed, or what scenarios would lead to them being put into action. The purpose of exposing such information is partly to act as a deterrent to Russian behaviour - and some officials acknowledge that they cannot be totally confident what will unfold. The Kremlin responded by saying talk of a "kill list" was "absolute fiction". "There is no such list. It's a fake," spokesperson Dmitry Peskov said. The US letter does not specify which part of the Russian intelligence or military services would be involved in such activity, and the FSB's Fifth Service is likely to be preparing political plans for any attempted take-over rather than directly enforcing control through arrests. "The Fifth Service is the FSB department that would be tasked to provide plans and scenarios for Ukraine's post regime change political future," explains Andrei Soldatov, an expert on the Russian intelligence services. Even though it is primarily a domestic service, the FSB has the lead role amongst Moscow's intelligence agencies in Ukraine. Back in 1992 Russia's Foreign Intelligence Service, the SVR, signed a deal with Ukraine and neighbouring states not to spy on them. That left the way open for the FSB which grew in power, particularly after its head in the late 1990s, Vladimir Putin, became Russia's leader. The SVR and military intelligence, the GRU, both still operate in Ukraine but the FSB leads on intelligence and influence operations. The current head of Service Five, Sergei Beseda, personally travelled to Ukraine in 2014 during the events surrounding the Maidan uprising that led to the removal of a pro-Russian government. Since 2014, a low-level war has been going on between Ukraine and Russian spy services. The Ukrainian Security Service has accused the FSB of carrying out sabotage and assassinations. In 2017, a senior Ukrainian intelligence official was killed in a car bomb. The FSB were also accused of running a high-level mole within the Ukrainian security services who was also allegedly involved a plan for an assassination. A recent report for the RUSI think-tank by Jack Watling and Neil Reynolds said that in July 2021 the Ukraine team of the Fifth Service was expanded to form the Ninth Directorate comprising around 200 officers. The FSB's current network could include further agents within the Ukrainian security and defence establishment ready to switch sides in the event of the crisis escalating whilst other agents could take control of institutions in local districts around the country. But how far such plans for political change and even arrests are put into action will depend on final decisions on the overall strategy from Russia's leaders.