Bulgaria–United States relations to work. Bulgaria became a member of the Warsaw Pact on May 14, 1955. Though no Soviet troops were stationed on Bulgarian soil, in 1968, Zhivkov sent a Bulgarian division to join Polish, Hungarian and Soviet troops to crush a popular uprising in Prague. In 1978, the Bulgarian secret police were implicated in the assassination in London of Georgi Markov, a Bulgarian dissident who was a correspondent for the BBC World Service, Deutsche Welle radio and the U.S. sponsored Radio Free Europe. Markov was assassinated with a poisoned umbrella on September 7, Zhivkov's birthday. The rise of democratic movements across
London Waterloo station Rail announced that platforms 20–24 would be fully refurbished in order to increase capacity at Waterloo by 30%. Communications manager Kevin Parker stressed that the international platforms were only designed to cope with six trains per hour, well below the expected capacity for commuter services. The platforms closed in September 2017 for the works, with a revised timetable to be published the following year. Waterloo station was to be the central London terminus for the proposed Heathrow Airtrack rail service. This project, promoted by British Airport Authority Limited (BAA), envisaged the construction of a spur, from on the Waterloo to