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
Wood Green ricin plot the second, Brylcreem. The Wood Green conspiracy allegations were also depicted critically in the 2007 documentary "Taking Liberties". Wood Green ricin plot The Wood Green ricin plot was a 2002 alleged bioterrorism plot to attack the London Underground with ricin poison. The Metropolitan Police Service arrested six suspects on 5 January 2003, with one more arrested two days later. Within two days, the Biological Weapon Identification Group at the Defence Science and Technology Laboratory in Porton Down were sure that there was no trace of ricin on any of the articles that were found. This fact was initially misreported to